* bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure [not found] ` <87r4s0opck.fsf@nemi.mork.no> @ 2012-07-25 4:08 ` Bjørn Mork 2012-07-25 4:34 ` Huang Ying 0 siblings, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-25 4:08 UTC (permalink / raw) To: Huang Ying Cc: Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern [-- Attachment #1: Type: text/plain, Size: 1052 bytes --] Enabling autosuspend for USB causes hotplug failure in the current linux-next. Newly plugged devices are not detected at all until the port/controller is manually powered on by writing "on" to power/control. Testing is pretty simple: 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done 2) wait for the controllers to suspend 3) plugin a new USB device I've bisected the regression down to this commit: commit 448bd857d48e69b33ef323739dc6d8ca20d4cda7 Author: Huang Ying <ying.huang@intel.com> Date: Sat Jun 23 10:23:51 2012 +0800 PCI/PM: add PCIe runtime D3cold support Looks like this somehow powers down my USB host controllers in such a way that they are unable to detect connections to their ports. The system is a pretty standard 4 year old intel based laptop. Full lspci listing is attached. Please let me know if you need further information. And please fix this before rc1. It effectively makes USB non-functional if autosuspend is enabled. Thanks, Bjørn [-- Attachment #2: lspci.txt --] [-- Type: text/plain, Size: 22272 bytes --] 00:00.0 Host bridge [0600]: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub [8086:2a40] (rev 07) Subsystem: Lenovo Device [17aa:20e0] Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR- INTx- Latency: 0 Capabilities: [e0] Vendor Specific Information: Len=0a <?> Kernel driver in use: agpgart-intel 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller]) Subsystem: Lenovo Device [17aa:20e4] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 45 Region 0: Memory at f0000000 (64-bit, non-prefetchable) [size=4M] Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M] Region 4: I/O ports at 1800 [size=8] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 41a1 Capabilities: [d0] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Kernel driver in use: i915 00:02.1 Display controller [0380]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a43] (rev 07) Subsystem: Lenovo Device [17aa:20e4] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Region 0: Memory at f0400000 (64-bit, non-prefetchable) [size=1M] Capabilities: [d0] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- 00:03.0 Communication controller [0780]: Intel Corporation Mobile 4 Series Chipset MEI Controller [8086:2a44] (rev 07) Subsystem: Lenovo Device [17aa:20e6] Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx+ Interrupt: pin A routed to IRQ 44 Region 0: Memory at f0826800 (64-bit, non-prefetchable) [size=16] Capabilities: [50] Power Management version 3 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME- Capabilities: [8c] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 00000000fee0300c Data: 4199 00:19.0 Ethernet controller [0200]: Intel Corporation 82567LM Gigabit Network Connection [8086:10f5] (rev 03) Subsystem: Lenovo Device [17aa:20ee] Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 20 Region 0: Memory at f0600000 (32-bit, non-prefetchable) [disabled] [size=128K] Region 1: Memory at f0625000 (32-bit, non-prefetchable) [disabled] [size=4K] Region 2: I/O ports at 1840 [disabled] [size=32] Capabilities: [c8] Power Management version 2 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=1 PME- Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+ Address: 00000000fee0300c Data: 4122 Capabilities: [e0] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: e1000e 00:1a.0 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 [8086:2937] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 20 Region 4: I/O ports at 1860 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1a.1 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 [8086:2938] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin B routed to IRQ 21 Region 4: I/O ports at 1880 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1a.2 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 [8086:2939] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin C routed to IRQ 22 Region 4: I/O ports at 18a0 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1a.7 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 [8086:293c] (rev 03) (prog-if 20 [EHCI]) Subsystem: Lenovo Device [17aa:20f1] Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin D routed to IRQ 23 Region 0: Memory at f0826c00 (32-bit, non-prefetchable) [size=1K] Capabilities: [50] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [58] Debug port: BAR=1 offset=00a0 Capabilities: [98] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: ehci_hcd 00:1b.0 Audio device [0403]: Intel Corporation 82801I (ICH9 Family) HD Audio Controller [8086:293e] (rev 03) Subsystem: Lenovo Device [17aa:20f2] Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Interrupt: pin B routed to IRQ 47 Region 0: Memory at f0620000 (64-bit, non-prefetchable) [size=16K] Capabilities: [50] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 00000000fee0300c Data: 41b1 Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE- FLReset+ DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+ MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #0, Speed unknown, Width x0, ASPM unknown, Latency L0 <64ns, L1 <1us ClockPM- Surprise- LLActRep- BwNot- LnkCtl: ASPM Disabled; Disabled- Retrain- CommClk- ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed unknown, Width x0, TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed- WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=ff Status: NegoPending- InProgress- VC1: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable- ID=0 ArbSelect=Fixed TC/VC=00 Status: NegoPending- InProgress- Capabilities: [130 v1] Root Complex Link Desc: PortNumber=0f ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: snd_hda_intel 00:1c.0 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 [8086:2940] (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=02, subordinate=02, sec-latency=0 I/O behind bridge: 00002000-00002fff Memory behind bridge: c0000000-c01fffff Prefetchable memory behind bridge: 00000000c0200000-00000000c03fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #1, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <4us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk- ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x0, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Slot #0, PowerLimit 6.500W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet+ CmdCplt+ HPIrq+ LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock- Changed: MRL- PresDet- LinkState- RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+ CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 4179 Capabilities: [90] Subsystem: Lenovo Device [17aa:20f3] Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed+ WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=ff Status: NegoPending- InProgress- Capabilities: [180 v1] Root Complex Link Desc: PortNumber=01 ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: pcieport 00:1c.1 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 [8086:2942] (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 00003000-00003fff Memory behind bridge: f0500000-f05fffff Prefetchable memory behind bridge: 00000000c0400000-00000000c05fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #2, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <256ns, L1 <4us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Slot #1, PowerLimit 6.500W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet+ CmdCplt+ HPIrq+ LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState+ RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+ CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 4181 Capabilities: [90] Subsystem: Lenovo Device [17aa:20f3] Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed+ WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01 Status: NegoPending- InProgress- Capabilities: [180 v1] Root Complex Link Desc: PortNumber=02 ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: pcieport 00:1d.0 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 [8086:2934] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 16 Region 4: I/O ports at 18c0 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1d.1 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 [8086:2935] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin B routed to IRQ 17 Region 4: I/O ports at 18e0 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1d.2 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 [8086:2936] (rev 03) (prog-if 00 [UHCI]) Subsystem: Lenovo Device [17aa:20f0] Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin C routed to IRQ 18 Region 4: I/O ports at 1c00 [size=32] Capabilities: [50] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: uhci_hcd 00:1d.7 USB controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 [8086:293a] (rev 03) (prog-if 20 [EHCI]) Subsystem: Lenovo Device [17aa:20f1] Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin D routed to IRQ 19 Region 0: Memory at f0827000 (32-bit, non-prefetchable) [size=1K] Capabilities: [50] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [58] Debug port: BAR=1 offset=00a0 Capabilities: [98] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: ehci_hcd 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev 93) (prog-if 01 [Subtractive decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Bus: primary=00, secondary=15, subordinate=15, sec-latency=32 I/O behind bridge: 0000f000-00000fff Memory behind bridge: fff00000-000fffff Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort+ <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA- VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [50] Subsystem: Lenovo Device [17aa:20f4] 00:1f.0 ISA bridge [0601]: Intel Corporation ICH9M-E LPC Interface Controller [8086:2917] (rev 03) Subsystem: Lenovo Device [17aa:20f5] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Capabilities: [e0] Vendor Specific Information: Len=0c <?> 00:1f.2 SATA controller [0106]: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 4 port SATA Controller [AHCI mode] [8086:2929] (rev 03) (prog-if 01 [AHCI 1.0]) Subsystem: Lenovo Device [17aa:20f8] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin B routed to IRQ 43 Region 0: I/O ports at 1c48 [size=8] Region 1: I/O ports at 183c [size=4] Region 2: I/O ports at 1c40 [size=8] Region 3: I/O ports at 1838 [size=4] Region 4: I/O ports at 1c20 [size=32] Region 5: Memory at f0826000 (32-bit, non-prefetchable) [size=2K] Capabilities: [80] MSI: Enable+ Count=1/16 Maskable- 64bit- Address: fee0300c Data: 4191 Capabilities: [70] Power Management version 3 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold-) Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME- Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004 Capabilities: [b0] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: ahci 00:1f.3 SMBus [0c05]: Intel Corporation 82801I (ICH9 Family) SMBus Controller [8086:2930] (rev 03) Subsystem: Lenovo Device [17aa:20f9] Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 23 Region 0: Memory at f0827400 (64-bit, non-prefetchable) [size=256] Region 4: I/O ports at 1c60 [size=32] Kernel driver in use: i801_smbus 03:00.0 Network controller [0280]: Intel Corporation Ultimate N WiFi Link 5300 [8086:4236] Subsystem: Intel Corporation Device [8086:1011] Physical Slot: 1 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 46 Region 0: Memory at f0500000 (64-bit, non-prefetchable) [size=8K] Capabilities: [c8] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 00000000fee0300c Data: 41a9 Capabilities: [e0] Express (v1) Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr+ TransPend- LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <128ns, L1 <32us ClockPM+ Surprise- LLActRep- BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- Capabilities: [100 v1] Advanced Error Reporting UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol- CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn- Capabilities: [140 v1] Device Serial Number 00-16-ea-ff-ff-b3-07-88 Kernel driver in use: iwlwifi ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 4:08 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Bjørn Mork @ 2012-07-25 4:34 ` Huang Ying 2012-07-25 9:58 ` Bjørn Mork 0 siblings, 1 reply; 89+ messages in thread From: Huang Ying @ 2012-07-25 4:34 UTC (permalink / raw) To: Bjørn Mork Cc: Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Hi, Bjorn, On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: > Enabling autosuspend for USB causes hotplug failure in the current > linux-next. Newly plugged devices are not detected at all until the > port/controller is manually powered on by writing "on" to power/control. > Testing is pretty simple: > > 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done Have you done: for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done ? If not, the pci device will not be suspended at all. > 2) wait for the controllers to suspend > 3) plugin a new USB device After plugin the new USB device, is there anything in dmesg? > > I've bisected the regression down to this commit: > > > commit 448bd857d48e69b33ef323739dc6d8ca20d4cda7 > Author: Huang Ying <ying.huang@intel.com> > Date: Sat Jun 23 10:23:51 2012 +0800 > > PCI/PM: add PCIe runtime D3cold support > > > Looks like this somehow powers down my USB host controllers in such a > way that they are unable to detect connections to their ports. The > system is a pretty standard 4 year old intel based laptop. Full lspci > listing is attached. > > Please let me know if you need further information. And please fix this > before rc1. It effectively makes USB non-functional if autosuspend is > enabled. Can you provide the output of the following command lines? grep . /sys/bus/pci/devices/*/power/* grep . /sys/bus/usb/devices/*/power/* lsusb After the controllers suspended. Best Reards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 4:34 ` Huang Ying @ 2012-07-25 9:58 ` Bjørn Mork 2012-07-25 13:30 ` huang ying 0 siblings, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-25 9:58 UTC (permalink / raw) To: Huang Ying Cc: Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern [-- Attachment #1: Type: text/plain, Size: 5738 bytes --] Huang Ying <ying.huang@intel.com> writes: > On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: >> Enabling autosuspend for USB causes hotplug failure in the current >> linux-next. Newly plugged devices are not detected at all until the >> port/controller is manually powered on by writing "on" to power/control. >> Testing is pretty simple: >> >> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done > > Have you done: > > for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done > > ? > > If not, the pci device will not be suspended at all. Yes, sorry for missing that. I had it automatically enabled. Yes, autosuspend for the PCI device and all child devices must be enabled for the device to be suspended at all, of course. >> 2) wait for the controllers to suspend >> 3) plugin a new USB device > > After plugin the new USB device, is there anything in dmesg? No. Absolutely nothing, so the USB devices is not enumerated. Another indication of the same: Plugging a device like an Android phone, which normally detects being connected to a host and presents a device type menu to the user, results in the charging LED lighting up but no menu. Trying to show the sequence of events: 1) the controllers are suspended: Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 2) I connect a new USB device here 3) I read all power/files triggering this warning (as expected), included for timing info - this happens a while after connecting the USB device: Jul 25 11:28:34 nemi kernel: [ 121.440558] WARNING! power/level is deprecated; use power/control instead 4) I wake up the usb2 bus I connected the device to, and it is immediately found (no info about power state change here?): nemi:/home/bjorn# echo on > /sys/bus/usb/devices/usb2/power/control Jul 25 11:29:32 nemi kernel: [ 179.121418] ehci_hcd 0000:00:1d.7: setting latency timer to 64 Jul 25 11:29:32 nemi kernel: [ 179.364088] usb 2-1: new high-speed USB device number 3 using ehci_hcd Jul 25 11:29:33 nemi kernel: [ 179.500042] usb 2-1: New USB device found, idVendor=0fce, idProduct=2138 Jul 25 11:29:33 nemi kernel: [ 179.500055] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Jul 25 11:29:33 nemi kernel: [ 179.500063] usb 2-1: Product: SEMC HSUSB Device Jul 25 11:29:33 nemi kernel: [ 179.500069] usb 2-1: Manufacturer: SEMC Jul 25 11:29:33 nemi kernel: [ 179.500075] usb 2-1: SerialNumber: 43423531314D42573144 Doing the same with commit 448bd857d reverted: 1) the controllers are suspended (to state D3? instead of D2?): Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 2) plugging a USB device causes immediate wakeup (and logs changes state to D0): Jul 25 11:34:43 nemi kernel: [ 78.575357] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D0 Jul 25 11:34:43 nemi kernel: [ 78.588162] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D0 Jul 25 11:34:43 nemi kernel: [ 78.588292] ehci_hcd 0000:00:1d.7: setting latency timer to 64 Jul 25 11:34:43 nemi kernel: [ 78.832337] usb 2-1: new high-speed USB device number 3 using ehci_hcd Jul 25 11:34:43 nemi kernel: [ 78.968286] usb 2-1: New USB device found, idVendor=0fce, idProduct=2138 Jul 25 11:34:43 nemi kernel: [ 78.968300] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Jul 25 11:34:43 nemi kernel: [ 78.968307] usb 2-1: Product: SEMC HSUSB Device Jul 25 11:34:43 nemi kernel: [ 78.968314] usb 2-1: Manufacturer: SEMC >> >> I've bisected the regression down to this commit: >> >> >> commit 448bd857d48e69b33ef323739dc6d8ca20d4cda7 >> Author: Huang Ying <ying.huang@intel.com> >> Date: Sat Jun 23 10:23:51 2012 +0800 >> >> PCI/PM: add PCIe runtime D3cold support >> >> >> Looks like this somehow powers down my USB host controllers in such a >> way that they are unable to detect connections to their ports. The >> system is a pretty standard 4 year old intel based laptop. Full lspci >> listing is attached. >> >> Please let me know if you need further information. And please fix this >> before rc1. It effectively makes USB non-functional if autosuspend is >> enabled. > > Can you provide the output of the following command lines? > > grep . /sys/bus/pci/devices/*/power/* > grep . /sys/bus/usb/devices/*/power/* > lsusb > > After the controllers suspended. I've attached two copies of this output: - powerstate-withbug.txt, from a plain next-20120724 kernel - powerstate-reverted.txt, from a next-20120724 kernel with commit 448bd857d reverted I cannot really see any interesting differences in these. But the D3/D2 difference in the kernel log might be of interest? Bjørn [-- Attachment #2: powerstate-withbug.txt --] [-- Type: text/plain, Size: 30392 bytes --] /sys/bus/usb/devices/1-0:1.0/power/async:enabled /sys/bus/usb/devices/1-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/1-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/1-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/1-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/1-6:1.0/power/async:enabled /sys/bus/usb/devices/1-6:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6:1.0/power/runtime_enabled:disabled /sys/bus/usb/devices/1-6:1.0/power/runtime_status:unsupported /sys/bus/usb/devices/1-6:1.0/power/runtime_usage:0 /sys/bus/usb/devices/1-6:1.1/power/async:enabled /sys/bus/usb/devices/1-6:1.1/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6:1.1/power/runtime_enabled:disabled /sys/bus/usb/devices/1-6:1.1/power/runtime_status:unsupported /sys/bus/usb/devices/1-6:1.1/power/runtime_usage:0 /sys/bus/usb/devices/1-6/power/active_duration:37124 /sys/bus/usb/devices/1-6/power/async:enabled /sys/bus/usb/devices/1-6/power/autosuspend:2 /sys/bus/usb/devices/1-6/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/1-6/power/connected_duration:119252 /sys/bus/usb/devices/1-6/power/control:auto /sys/bus/usb/devices/1-6/power/level:auto /sys/bus/usb/devices/1-6/power/persist:1 /sys/bus/usb/devices/1-6/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6/power/runtime_active_time:36896 /sys/bus/usb/devices/1-6/power/runtime_enabled:enabled /sys/bus/usb/devices/1-6/power/runtime_status:suspended /sys/bus/usb/devices/1-6/power/runtime_suspended_time:82112 /sys/bus/usb/devices/1-6/power/runtime_usage:0 /sys/bus/usb/devices/2-0:1.0/power/async:enabled /sys/bus/usb/devices/2-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/2-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/2-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/2-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.0/power/async:enabled /sys/bus/usb/devices/2-4:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.0/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.0/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.19/power/async:enabled /sys/bus/usb/devices/2-4:1.19/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.19/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.19/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.19/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.20/power/async:enabled /sys/bus/usb/devices/2-4:1.20/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.20/power/runtime_enabled:disabled /sys/bus/usb/devices/2-4:1.20/power/runtime_status:unsupported /sys/bus/usb/devices/2-4:1.20/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.2/power/async:enabled /sys/bus/usb/devices/2-4:1.2/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.2/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.2/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.2/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.3/power/async:enabled /sys/bus/usb/devices/2-4:1.3/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.3/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.3/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.3/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.8/power/async:enabled /sys/bus/usb/devices/2-4:1.8/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.8/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.8/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.8/power/runtime_usage:0 /sys/bus/usb/devices/2-4/power/active_duration:36976 /sys/bus/usb/devices/2-4/power/async:enabled /sys/bus/usb/devices/2-4/power/autosuspend:2 /sys/bus/usb/devices/2-4/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/2-4/power/connected_duration:119000 /sys/bus/usb/devices/2-4/power/control:auto /sys/bus/usb/devices/2-4/power/level:auto /sys/bus/usb/devices/2-4/power/persist:1 /sys/bus/usb/devices/2-4/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4/power/runtime_active_time:36748 /sys/bus/usb/devices/2-4/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4/power/runtime_status:suspended /sys/bus/usb/devices/2-4/power/runtime_suspended_time:82008 /sys/bus/usb/devices/2-4/power/runtime_usage:0 /sys/bus/usb/devices/2-4/power/wakeup:disabled /sys/bus/usb/devices/3-0:1.0/power/async:enabled /sys/bus/usb/devices/3-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/3-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/3-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/3-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/3-2:1.0/power/async:enabled /sys/bus/usb/devices/3-2:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/3-2:1.0/power/runtime_enabled:disabled /sys/bus/usb/devices/3-2:1.0/power/runtime_status:unsupported /sys/bus/usb/devices/3-2:1.0/power/runtime_usage:0 /sys/bus/usb/devices/3-2/power/active_duration:36736 /sys/bus/usb/devices/3-2/power/async:enabled /sys/bus/usb/devices/3-2/power/autosuspend:2 /sys/bus/usb/devices/3-2/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/3-2/power/connected_duration:118616 /sys/bus/usb/devices/3-2/power/control:auto /sys/bus/usb/devices/3-2/power/level:auto /sys/bus/usb/devices/3-2/power/persist:1 /sys/bus/usb/devices/3-2/power/runtime_active_kids:0 /sys/bus/usb/devices/3-2/power/runtime_active_time:36496 /sys/bus/usb/devices/3-2/power/runtime_enabled:enabled /sys/bus/usb/devices/3-2/power/runtime_status:suspended /sys/bus/usb/devices/3-2/power/runtime_suspended_time:81864 /sys/bus/usb/devices/3-2/power/runtime_usage:0 /sys/bus/usb/devices/3-2/power/wakeup:disabled /sys/bus/usb/devices/4-0:1.0/power/async:enabled /sys/bus/usb/devices/4-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/4-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/4-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/4-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.0/power/async:enabled /sys/bus/usb/devices/4-2:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2:1.0/power/runtime_status:suspended /sys/bus/usb/devices/4-2:1.0/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.1/power/async:enabled /sys/bus/usb/devices/4-2:1.1/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.1/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2:1.1/power/runtime_status:suspended /sys/bus/usb/devices/4-2:1.1/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.2/power/async:enabled /sys/bus/usb/devices/4-2:1.2/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.2/power/runtime_enabled:disabled /sys/bus/usb/devices/4-2:1.2/power/runtime_status:unsupported /sys/bus/usb/devices/4-2:1.2/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.3/power/async:enabled /sys/bus/usb/devices/4-2:1.3/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.3/power/runtime_enabled:disabled /sys/bus/usb/devices/4-2:1.3/power/runtime_status:unsupported /sys/bus/usb/devices/4-2:1.3/power/runtime_usage:0 /sys/bus/usb/devices/4-2/power/active_duration:26552 /sys/bus/usb/devices/4-2/power/async:enabled /sys/bus/usb/devices/4-2/power/autosuspend:2 /sys/bus/usb/devices/4-2/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/4-2/power/connected_duration:118200 /sys/bus/usb/devices/4-2/power/control:auto /sys/bus/usb/devices/4-2/power/level:auto /sys/bus/usb/devices/4-2/power/persist:1 /sys/bus/usb/devices/4-2/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2/power/runtime_active_time:26376 /sys/bus/usb/devices/4-2/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2/power/runtime_status:suspended /sys/bus/usb/devices/4-2/power/runtime_suspended_time:91568 /sys/bus/usb/devices/4-2/power/runtime_usage:0 /sys/bus/usb/devices/4-2/power/wakeup:disabled 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/sys/bus/pci/devices/0000:00:1d.1/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1d.1/power/runtime_status:suspended /sys/bus/pci/devices/0000:00:1d.1/power/runtime_suspended_time:82436 /sys/bus/pci/devices/0000:00:1d.1/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup:enabled /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_abort_count:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_active:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_active_count:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_count:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_expire_count:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_last_time_ms:1802 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_max_time_ms:0 /sys/bus/pci/devices/0000:00:1d.1/power/wakeup_total_time_ms:0 /sys/bus/pci/devices/0000:00:1d.2/power/async:enabled /sys/bus/pci/devices/0000:00:1d.2/power/control:auto /sys/bus/pci/devices/0000:00:1d.2/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1d.2/power/runtime_active_time:37220 /sys/bus/pci/devices/0000:00:1d.2/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1d.2/power/runtime_status:suspended /sys/bus/pci/devices/0000:00:1d.2/power/runtime_suspended_time:82432 /sys/bus/pci/devices/0000:00:1d.2/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup:enabled /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_abort_count:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_active:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_active_count:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_count:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_expire_count:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_last_time_ms:1805 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_max_time_ms:0 /sys/bus/pci/devices/0000:00:1d.2/power/wakeup_total_time_ms:0 /sys/bus/pci/devices/0000:00:1d.7/power/async:enabled /sys/bus/pci/devices/0000:00:1d.7/power/control:auto /sys/bus/pci/devices/0000:00:1d.7/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1d.7/power/runtime_active_time:40060 /sys/bus/pci/devices/0000:00:1d.7/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1d.7/power/runtime_status:suspended /sys/bus/pci/devices/0000:00:1d.7/power/runtime_suspended_time:79628 /sys/bus/pci/devices/0000:00:1d.7/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup:enabled /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_abort_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_active:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_active_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_expire_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_last_time_ms:1781 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_max_time_ms:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_total_time_ms:0 /sys/bus/pci/devices/0000:00:1e.0/power/async:enabled /sys/bus/pci/devices/0000:00:1e.0/power/control:auto /sys/bus/pci/devices/0000:00:1e.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_active_time:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_enabled:disabled /sys/bus/pci/devices/0000:00:1e.0/power/runtime_status:unsupported /sys/bus/pci/devices/0000:00:1e.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1e.0/power/wakeup:disabled /sys/bus/pci/devices/0000:00:1f.0/power/async:enabled /sys/bus/pci/devices/0000:00:1f.0/power/control:auto /sys/bus/pci/devices/0000:00:1f.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_active_time:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_enabled:disabled /sys/bus/pci/devices/0000:00:1f.0/power/runtime_status:unsupported /sys/bus/pci/devices/0000:00:1f.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1f.2/power/async:enabled /sys/bus/pci/devices/0000:00:1f.2/power/control:auto /sys/bus/pci/devices/0000:00:1f.2/power/runtime_active_kids:4 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_active_time:119672 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1f.2/power/runtime_status:active /sys/bus/pci/devices/0000:00:1f.2/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_usage:1 /sys/bus/pci/devices/0000:00:1f.2/power/wakeup:disabled /sys/bus/pci/devices/0000:00:1f.3/power/async:enabled /sys/bus/pci/devices/0000:00:1f.3/power/control:auto /sys/bus/pci/devices/0000:00:1f.3/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_active_time:105156 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1f.3/power/runtime_status:active /sys/bus/pci/devices/0000:00:1f.3/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_usage:1 /sys/bus/pci/devices/0000:03:00.0/power/async:enabled /sys/bus/pci/devices/0000:03:00.0/power/control:auto /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_time:104580 /sys/bus/pci/devices/0000:03:00.0/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:03:00.0/power/runtime_status:active /sys/bus/pci/devices/0000:03:00.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_usage:1 /sys/bus/pci/devices/0000:03:00.0/power/wakeup:disabled Bus 001 Device 004: ID 17ef:4807 Lenovo UVC Camera Bus 002 Device 002: ID 1199:68a2 Sierra Wireless, Inc. Bus 003 Device 002: ID 08ff:2810 AuthenTec, Inc. AES2810 Bus 004 Device 002: ID 0a5c:2145 Broadcom Corp. Bluetooth with Enhanced Data Rate II Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub [-- Attachment #3: powerstate-reverted.txt --] [-- Type: text/plain, Size: 31221 bytes --] /sys/bus/usb/devices/1-0:1.0/power/async:enabled /sys/bus/usb/devices/1-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/1-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/1-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/1-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/1-6:1.0/power/async:enabled /sys/bus/usb/devices/1-6:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6:1.0/power/runtime_enabled:disabled /sys/bus/usb/devices/1-6:1.0/power/runtime_status:unsupported /sys/bus/usb/devices/1-6:1.0/power/runtime_usage:0 /sys/bus/usb/devices/1-6:1.1/power/async:enabled /sys/bus/usb/devices/1-6:1.1/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6:1.1/power/runtime_enabled:disabled /sys/bus/usb/devices/1-6:1.1/power/runtime_status:unsupported /sys/bus/usb/devices/1-6:1.1/power/runtime_usage:0 /sys/bus/usb/devices/1-6/power/active_duration:35204 /sys/bus/usb/devices/1-6/power/async:enabled /sys/bus/usb/devices/1-6/power/autosuspend:2 /sys/bus/usb/devices/1-6/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/1-6/power/connected_duration:70960 /sys/bus/usb/devices/1-6/power/control:auto /sys/bus/usb/devices/1-6/power/level:auto /sys/bus/usb/devices/1-6/power/persist:1 /sys/bus/usb/devices/1-6/power/runtime_active_kids:0 /sys/bus/usb/devices/1-6/power/runtime_active_time:34976 /sys/bus/usb/devices/1-6/power/runtime_enabled:enabled /sys/bus/usb/devices/1-6/power/runtime_status:suspended /sys/bus/usb/devices/1-6/power/runtime_suspended_time:35740 /sys/bus/usb/devices/1-6/power/runtime_usage:0 /sys/bus/usb/devices/2-0:1.0/power/async:enabled /sys/bus/usb/devices/2-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/2-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/2-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/2-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.0/power/async:enabled /sys/bus/usb/devices/2-4:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.0/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.0/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.19/power/async:enabled /sys/bus/usb/devices/2-4:1.19/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.19/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.19/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.19/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.20/power/async:enabled /sys/bus/usb/devices/2-4:1.20/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.20/power/runtime_enabled:disabled /sys/bus/usb/devices/2-4:1.20/power/runtime_status:unsupported /sys/bus/usb/devices/2-4:1.20/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.2/power/async:enabled /sys/bus/usb/devices/2-4:1.2/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.2/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.2/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.2/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.3/power/async:enabled /sys/bus/usb/devices/2-4:1.3/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.3/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.3/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.3/power/runtime_usage:0 /sys/bus/usb/devices/2-4:1.8/power/async:enabled /sys/bus/usb/devices/2-4:1.8/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4:1.8/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4:1.8/power/runtime_status:suspended /sys/bus/usb/devices/2-4:1.8/power/runtime_usage:0 /sys/bus/usb/devices/2-4/power/active_duration:35056 /sys/bus/usb/devices/2-4/power/async:enabled /sys/bus/usb/devices/2-4/power/autosuspend:2 /sys/bus/usb/devices/2-4/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/2-4/power/connected_duration:70708 /sys/bus/usb/devices/2-4/power/control:auto /sys/bus/usb/devices/2-4/power/level:auto /sys/bus/usb/devices/2-4/power/persist:1 /sys/bus/usb/devices/2-4/power/runtime_active_kids:0 /sys/bus/usb/devices/2-4/power/runtime_active_time:34828 /sys/bus/usb/devices/2-4/power/runtime_enabled:enabled /sys/bus/usb/devices/2-4/power/runtime_status:suspended /sys/bus/usb/devices/2-4/power/runtime_suspended_time:35636 /sys/bus/usb/devices/2-4/power/runtime_usage:0 /sys/bus/usb/devices/2-4/power/wakeup:disabled /sys/bus/usb/devices/3-0:1.0/power/async:enabled /sys/bus/usb/devices/3-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/3-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/3-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/3-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/3-2:1.0/power/async:enabled /sys/bus/usb/devices/3-2:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/3-2:1.0/power/runtime_enabled:disabled /sys/bus/usb/devices/3-2:1.0/power/runtime_status:unsupported /sys/bus/usb/devices/3-2:1.0/power/runtime_usage:0 /sys/bus/usb/devices/3-2/power/active_duration:34820 /sys/bus/usb/devices/3-2/power/async:enabled /sys/bus/usb/devices/3-2/power/autosuspend:2 /sys/bus/usb/devices/3-2/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/3-2/power/connected_duration:70324 /sys/bus/usb/devices/3-2/power/control:auto /sys/bus/usb/devices/3-2/power/level:auto /sys/bus/usb/devices/3-2/power/persist:1 /sys/bus/usb/devices/3-2/power/runtime_active_kids:0 /sys/bus/usb/devices/3-2/power/runtime_active_time:34580 /sys/bus/usb/devices/3-2/power/runtime_enabled:enabled /sys/bus/usb/devices/3-2/power/runtime_status:suspended /sys/bus/usb/devices/3-2/power/runtime_suspended_time:35488 /sys/bus/usb/devices/3-2/power/runtime_usage:0 /sys/bus/usb/devices/3-2/power/wakeup:disabled /sys/bus/usb/devices/4-0:1.0/power/async:enabled /sys/bus/usb/devices/4-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/4-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/4-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/4-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.0/power/async:enabled /sys/bus/usb/devices/4-2:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2:1.0/power/runtime_status:suspended /sys/bus/usb/devices/4-2:1.0/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.1/power/async:enabled /sys/bus/usb/devices/4-2:1.1/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.1/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2:1.1/power/runtime_status:suspended /sys/bus/usb/devices/4-2:1.1/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.2/power/async:enabled /sys/bus/usb/devices/4-2:1.2/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.2/power/runtime_enabled:disabled /sys/bus/usb/devices/4-2:1.2/power/runtime_status:unsupported /sys/bus/usb/devices/4-2:1.2/power/runtime_usage:0 /sys/bus/usb/devices/4-2:1.3/power/async:enabled /sys/bus/usb/devices/4-2:1.3/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2:1.3/power/runtime_enabled:disabled /sys/bus/usb/devices/4-2:1.3/power/runtime_status:unsupported /sys/bus/usb/devices/4-2:1.3/power/runtime_usage:0 /sys/bus/usb/devices/4-2/power/active_duration:25788 /sys/bus/usb/devices/4-2/power/async:enabled /sys/bus/usb/devices/4-2/power/autosuspend:2 /sys/bus/usb/devices/4-2/power/autosuspend_delay_ms:2000 /sys/bus/usb/devices/4-2/power/connected_duration:69908 /sys/bus/usb/devices/4-2/power/control:auto /sys/bus/usb/devices/4-2/power/level:auto /sys/bus/usb/devices/4-2/power/persist:1 /sys/bus/usb/devices/4-2/power/runtime_active_kids:0 /sys/bus/usb/devices/4-2/power/runtime_active_time:25612 /sys/bus/usb/devices/4-2/power/runtime_enabled:enabled /sys/bus/usb/devices/4-2/power/runtime_status:suspended /sys/bus/usb/devices/4-2/power/runtime_suspended_time:44040 /sys/bus/usb/devices/4-2/power/runtime_usage:0 /sys/bus/usb/devices/4-2/power/wakeup:disabled /sys/bus/usb/devices/5-0:1.0/power/async:enabled /sys/bus/usb/devices/5-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/5-0:1.0/power/runtime_enabled:enabled /sys/bus/usb/devices/5-0:1.0/power/runtime_status:suspended /sys/bus/usb/devices/5-0:1.0/power/runtime_usage:0 /sys/bus/usb/devices/6-0:1.0/power/async:enabled /sys/bus/usb/devices/6-0:1.0/power/runtime_active_kids:0 /sys/bus/usb/devices/6-0:1.0/power/runtime_enabled:enabled 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/sys/bus/pci/devices/0000:00:1d.7/power/wakeup_active:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_active_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_expire_count:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_last_time_ms:1657 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_max_time_ms:0 /sys/bus/pci/devices/0000:00:1d.7/power/wakeup_total_time_ms:0 /sys/bus/pci/devices/0000:00:1e.0/power/async:enabled /sys/bus/pci/devices/0000:00:1e.0/power/control:auto /sys/bus/pci/devices/0000:00:1e.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_active_time:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_enabled:disabled /sys/bus/pci/devices/0000:00:1e.0/power/runtime_status:unsupported /sys/bus/pci/devices/0000:00:1e.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1e.0/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1e.0/power/wakeup:disabled /sys/bus/pci/devices/0000:00:1f.0/power/async:enabled /sys/bus/pci/devices/0000:00:1f.0/power/control:auto /sys/bus/pci/devices/0000:00:1f.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_active_time:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_enabled:disabled /sys/bus/pci/devices/0000:00:1f.0/power/runtime_status:unsupported /sys/bus/pci/devices/0000:00:1f.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.0/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1f.2/power/async:enabled /sys/bus/pci/devices/0000:00:1f.2/power/control:auto /sys/bus/pci/devices/0000:00:1f.2/power/runtime_active_kids:4 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_active_time:71380 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1f.2/power/runtime_status:active /sys/bus/pci/devices/0000:00:1f.2/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.2/power/runtime_usage:1 /sys/bus/pci/devices/0000:00:1f.2/power/wakeup:disabled /sys/bus/pci/devices/0000:00:1f.3/power/async:enabled /sys/bus/pci/devices/0000:00:1f.3/power/control:auto /sys/bus/pci/devices/0000:00:1f.3/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_active_time:54952 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1f.3/power/runtime_status:active /sys/bus/pci/devices/0000:00:1f.3/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:00:1f.3/power/runtime_usage:1 /sys/bus/pci/devices/0000:03:00.0/power/async:enabled /sys/bus/pci/devices/0000:03:00.0/power/control:auto /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_time:56836 /sys/bus/pci/devices/0000:03:00.0/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:03:00.0/power/runtime_status:active /sys/bus/pci/devices/0000:03:00.0/power/runtime_suspended_time:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_usage:1 /sys/bus/pci/devices/0000:03:00.0/power/wakeup:disabled Bus 001 Device 004: ID 17ef:4807 Lenovo UVC Camera Bus 002 Device 002: ID 1199:68a2 Sierra Wireless, Inc. Bus 003 Device 002: ID 08ff:2810 AuthenTec, Inc. AES2810 Bus 004 Device 002: ID 0a5c:2145 Broadcom Corp. Bluetooth with Enhanced Data Rate II Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 004: ID 17ef:4807 Lenovo UVC Camera Bus 002 Device 003: ID 0fce:2138 Sony Ericsson Mobile Communications AB Xperia X10 mini pro (Debug) Bus 002 Device 002: ID 1199:68a2 Sierra Wireless, Inc. Bus 003 Device 002: ID 08ff:2810 AuthenTec, Inc. AES2810 Bus 004 Device 002: ID 0a5c:2145 Broadcom Corp. Bluetooth with Enhanced Data Rate II Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 9:58 ` Bjørn Mork @ 2012-07-25 13:30 ` huang ying 2012-07-25 13:58 ` Bjørn Mork 2012-07-25 19:51 ` [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() Rafael J. Wysocki 0 siblings, 2 replies; 89+ messages in thread From: huang ying @ 2012-07-25 13:30 UTC (permalink / raw) To: Bjørn Mork Cc: Huang Ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Hi, Bjorn, Thank you very much for your detailed information. On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: > Huang Ying <ying.huang@intel.com> writes: >> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: >>> Enabling autosuspend for USB causes hotplug failure in the current >>> linux-next. Newly plugged devices are not detected at all until the >>> port/controller is manually powered on by writing "on" to power/control. >>> Testing is pretty simple: >>> >>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done >> >> Have you done: >> >> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done >> >> ? >> >> If not, the pci device will not be suspended at all. > > Yes, sorry for missing that. I had it automatically enabled. Yes, > autosuspend for the PCI device and all child devices must be enabled for > the device to be suspended at all, of course. > >>> 2) wait for the controllers to suspend >>> 3) plugin a new USB device >> >> After plugin the new USB device, is there anything in dmesg? > > No. Absolutely nothing, so the USB devices is not enumerated. Another > indication of the same: Plugging a device like an Android phone, which > normally detects being connected to a host and presents a device type > menu to the user, results in the charging LED lighting up but no menu. > > > Trying to show the sequence of events: > > 1) the controllers are suspended: > > Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 > Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 Here uhci controller is put into D2 [snip] > > Doing the same with commit 448bd857d reverted: > > > 1) the controllers are suspended (to state D3? instead of D2?): > > Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 > Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 > Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 > Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 > Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). And the uhci controller on your system may not work properly under D2 state, while OK in D3 state, and the commit will make uhci controller choose D2 instead of D3. Please try following command line before testing. for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done And please provide the output of the following command line. acpidump Best Regards, Huang Ying [snip] ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 13:30 ` huang ying @ 2012-07-25 13:58 ` Bjørn Mork 2012-07-25 18:56 ` Rafael J. Wysocki ` (2 more replies) 2012-07-25 19:51 ` [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() Rafael J. Wysocki 1 sibling, 3 replies; 89+ messages in thread From: Bjørn Mork @ 2012-07-25 13:58 UTC (permalink / raw) To: huang ying Cc: Huang Ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern huang ying <huang.ying.caritas@gmail.com> writes: > Hi, Bjorn, > > Thank you very much for your detailed information. > > On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: >> Huang Ying <ying.huang@intel.com> writes: >>> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: >>>> Enabling autosuspend for USB causes hotplug failure in the current >>>> linux-next. Newly plugged devices are not detected at all until the >>>> port/controller is manually powered on by writing "on" to power/control. >>>> Testing is pretty simple: >>>> >>>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done >>> >>> Have you done: >>> >>> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done >>> >>> ? >>> >>> If not, the pci device will not be suspended at all. >> >> Yes, sorry for missing that. I had it automatically enabled. Yes, >> autosuspend for the PCI device and all child devices must be enabled for >> the device to be suspended at all, of course. >> >>>> 2) wait for the controllers to suspend >>>> 3) plugin a new USB device >>> >>> After plugin the new USB device, is there anything in dmesg? >> >> No. Absolutely nothing, so the USB devices is not enumerated. Another >> indication of the same: Plugging a device like an Android phone, which >> normally detects being connected to a host and presents a device type >> menu to the user, results in the charging LED lighting up but no menu. >> >> >> Trying to show the sequence of events: >> >> 1) the controllers are suspended: >> >> Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 >> Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 >> Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 >> Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 >> Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 > > Here uhci controller is put into D2 > > [snip] >> >> Doing the same with commit 448bd857d reverted: >> >> >> 1) the controllers are suspended (to state D3? instead of D2?): >> >> Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 >> Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 >> Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 >> Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 >> Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 > > With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). > > And the uhci controller on your system may not work properly under D2 > state, while OK in D3 state, and the commit will make uhci controller > choose D2 instead of D3. > > Please try following command line before testing. > > for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done That made it work. The USB controllers ended up in D4 though: Jul 25 15:52:33 nemi kernel: [ 152.753280] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D0 Jul 25 15:52:33 nemi kernel: [ 152.753453] uhci_hcd 0000:00:1a.0: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.753619] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D4 Jul 25 15:52:33 nemi kernel: [ 152.753875] uhci_hcd 0000:00:1a.1: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.754153] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D0 Jul 25 15:52:33 nemi kernel: [ 152.754279] uhci_hcd 0000:00:1a.2: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.754432] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D4 Jul 25 15:52:33 nemi kernel: [ 152.754668] ehci_hcd 0000:00:1a.7: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.768089] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 Jul 25 15:52:33 nemi kernel: [ 152.768573] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D0 Jul 25 15:52:33 nemi kernel: [ 152.768726] uhci_hcd 0000:00:1d.0: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.768891] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D4 Jul 25 15:52:33 nemi kernel: [ 152.769144] uhci_hcd 0000:00:1d.1: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.769530] uhci_hcd 0000:00:1d.2: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.769902] ehci_hcd 0000:00:1d.7: setting latency timer to 64 Jul 25 15:52:33 nemi kernel: [ 152.784189] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 was that expected? Anyway, waking up the controller from this state by plugging a USB device works, so it's a perfectly OK workaround. Is this something that could/should be implemented as a system specific quirk, or is the problem more generic? Even if it is a ACPI implementation issue I would expect it to be common to a number of Lenovo laptops of the same generation as mine (~2008). > And please provide the output of the following command line. > > acpidump Attached. Thanks a lot for all your help debugging this issue. Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 13:58 ` Bjørn Mork @ 2012-07-25 18:56 ` Rafael J. Wysocki 2012-07-25 20:02 ` Rafael J. Wysocki 2012-07-26 8:54 ` Huang Ying 2 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-25 18:56 UTC (permalink / raw) To: Bjørn Mork Cc: huang ying, Huang Ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Wednesday, July 25, 2012, Bjørn Mork wrote: > huang ying <huang.ying.caritas@gmail.com> writes: > > > Hi, Bjorn, > > > > Thank you very much for your detailed information. > > > > On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: > >> Huang Ying <ying.huang@intel.com> writes: > >>> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: > >>>> Enabling autosuspend for USB causes hotplug failure in the current > >>>> linux-next. Newly plugged devices are not detected at all until the > >>>> port/controller is manually powered on by writing "on" to power/control. > >>>> Testing is pretty simple: > >>>> > >>>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done > >>> > >>> Have you done: > >>> > >>> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done > >>> > >>> ? > >>> > >>> If not, the pci device will not be suspended at all. > >> > >> Yes, sorry for missing that. I had it automatically enabled. Yes, > >> autosuspend for the PCI device and all child devices must be enabled for > >> the device to be suspended at all, of course. > >> > >>>> 2) wait for the controllers to suspend > >>>> 3) plugin a new USB device > >>> > >>> After plugin the new USB device, is there anything in dmesg? > >> > >> No. Absolutely nothing, so the USB devices is not enumerated. Another > >> indication of the same: Plugging a device like an Android phone, which > >> normally detects being connected to a host and presents a device type > >> menu to the user, results in the charging LED lighting up but no menu. > >> > >> > >> Trying to show the sequence of events: > >> > >> 1) the controllers are suspended: > >> > >> Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > >> Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 > > > > Here uhci controller is put into D2 > > > > [snip] > >> > >> Doing the same with commit 448bd857d reverted: > >> > >> > >> 1) the controllers are suspended (to state D3? instead of D2?): > >> > >> Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 > >> Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 > > > > With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). > > > > And the uhci controller on your system may not work properly under D2 > > state, while OK in D3 state, and the commit will make uhci controller > > choose D2 instead of D3. > > > > Please try following command line before testing. > > > > for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done > > That made it work. The USB controllers ended up in D4 though: The D4 really is D3_cold. I'll send a patch to fix the state labeling. Thanks, Rafael > Jul 25 15:52:33 nemi kernel: [ 152.753280] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.753453] uhci_hcd 0000:00:1a.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.753619] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.753875] uhci_hcd 0000:00:1a.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754153] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.754279] uhci_hcd 0000:00:1a.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754432] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.754668] ehci_hcd 0000:00:1a.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768089] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.768573] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.768726] uhci_hcd 0000:00:1d.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768891] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.769144] uhci_hcd 0000:00:1d.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769530] uhci_hcd 0000:00:1d.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769902] ehci_hcd 0000:00:1d.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.784189] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > > > was that expected? Anyway, waking up the controller from this state by > plugging a USB device works, so it's a perfectly OK workaround. Is this > something that could/should be implemented as a system specific quirk, > or is the problem more generic? Even if it is a ACPI implementation > issue I would expect it to be common to a number of Lenovo laptops of > the same generation as mine (~2008). > > > And please provide the output of the following command line. > > > > acpidump > > Attached. Thanks a lot for all your help debugging this issue. > > > Bjørn > > > ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 13:58 ` Bjørn Mork 2012-07-25 18:56 ` Rafael J. Wysocki @ 2012-07-25 20:02 ` Rafael J. Wysocki 2012-07-25 22:36 ` Bjørn Mork 2012-07-26 2:38 ` Huang Ying 2012-07-26 8:54 ` Huang Ying 2 siblings, 2 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-25 20:02 UTC (permalink / raw) To: Bjørn Mork, Huang Ying Cc: huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Wednesday, July 25, 2012, Bjørn Mork wrote: > huang ying <huang.ying.caritas@gmail.com> writes: > > > Hi, Bjorn, > > > > Thank you very much for your detailed information. > > > > On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: > >> Huang Ying <ying.huang@intel.com> writes: > >>> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: > >>>> Enabling autosuspend for USB causes hotplug failure in the current > >>>> linux-next. Newly plugged devices are not detected at all until the > >>>> port/controller is manually powered on by writing "on" to power/control. > >>>> Testing is pretty simple: > >>>> > >>>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done > >>> > >>> Have you done: > >>> > >>> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done > >>> > >>> ? > >>> > >>> If not, the pci device will not be suspended at all. > >> > >> Yes, sorry for missing that. I had it automatically enabled. Yes, > >> autosuspend for the PCI device and all child devices must be enabled for > >> the device to be suspended at all, of course. > >> > >>>> 2) wait for the controllers to suspend > >>>> 3) plugin a new USB device > >>> > >>> After plugin the new USB device, is there anything in dmesg? > >> > >> No. Absolutely nothing, so the USB devices is not enumerated. Another > >> indication of the same: Plugging a device like an Android phone, which > >> normally detects being connected to a host and presents a device type > >> menu to the user, results in the charging LED lighting up but no menu. > >> > >> > >> Trying to show the sequence of events: > >> > >> 1) the controllers are suspended: > >> > >> Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > >> Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 > > > > Here uhci controller is put into D2 > > > > [snip] > >> > >> Doing the same with commit 448bd857d reverted: > >> > >> > >> 1) the controllers are suspended (to state D3? instead of D2?): > >> > >> Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 > >> Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 > > > > With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). > > > > And the uhci controller on your system may not work properly under D2 > > state, while OK in D3 state, and the commit will make uhci controller > > choose D2 instead of D3. > > > > Please try following command line before testing. > > > > for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done > > That made it work. The USB controllers ended up in D4 though: > > Jul 25 15:52:33 nemi kernel: [ 152.753280] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.753453] uhci_hcd 0000:00:1a.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.753619] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.753875] uhci_hcd 0000:00:1a.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754153] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.754279] uhci_hcd 0000:00:1a.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754432] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.754668] ehci_hcd 0000:00:1a.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768089] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.768573] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.768726] uhci_hcd 0000:00:1d.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768891] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.769144] uhci_hcd 0000:00:1d.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769530] uhci_hcd 0000:00:1d.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769902] ehci_hcd 0000:00:1d.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.784189] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > > > was that expected? Anyway, waking up the controller from this state by > plugging a USB device works, so it's a perfectly OK workaround. Is this > something that could/should be implemented as a system specific quirk, > or is the problem more generic? Even if it is a ACPI implementation > issue I would expect it to be common to a number of Lenovo laptops of > the same generation as mine (~2008). > > > And please provide the output of the following command line. > > > > acpidump > > Attached. Thanks a lot for all your help debugging this issue. This is not really necessary. The problem is the change of behavior I was worried about some time ago. Namely, the device in question apparently doesn't support ACPI D3_hot, so acpi_pm_device_sleep_state() returns D2 as the target state, where it would return D3(cold) before the commit in question. To fix the regression, we'd need to reverse the current initial value of the d3cold_allowed flag so that it is set to "true" by default and only set to "false" for devices where we suspect there may be problems with D3_cold (like PCI Express ports). Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 20:02 ` Rafael J. Wysocki @ 2012-07-25 22:36 ` Bjørn Mork 2012-07-26 2:38 ` Huang Ying 2012-07-26 2:38 ` Huang Ying 1 sibling, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-25 22:36 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Huang Ying, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern "Rafael J. Wysocki" <rjw@sisk.pl> writes: > This is not really necessary. The problem is the change of behavior I was > worried about some time ago. > > Namely, the device in question apparently doesn't support ACPI D3_hot, > so acpi_pm_device_sleep_state() returns D2 as the target state, where it > would return D3(cold) before the commit in question. > > To fix the regression, we'd need to reverse the current initial value of > the d3cold_allowed flag so that it is set to "true" by default and only > set to "false" for devices where we suspect there may be problems with > D3_cold (like PCI Express ports). Good. May I also request a few lines describing d3cold_allowed in e.g Documentation/ABI/testing/sysfs-bus-pci? I must admit that I thought that was the policy for any new sysfs file, but it seems that is only in the USB subsystem? Anyway, I believe it ought to be a requirement. If we are meant to tweak some knob, then we must known how and when to do so. If not, then why add it in the first place? Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 22:36 ` Bjørn Mork @ 2012-07-26 2:38 ` Huang Ying 0 siblings, 0 replies; 89+ messages in thread From: Huang Ying @ 2012-07-26 2:38 UTC (permalink / raw) To: Bjørn Mork Cc: Rafael J. Wysocki, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Thu, 2012-07-26 at 00:36 +0200, Bjørn Mork wrote: > "Rafael J. Wysocki" <rjw@sisk.pl> writes: > > > This is not really necessary. The problem is the change of behavior I was > > worried about some time ago. > > > > Namely, the device in question apparently doesn't support ACPI D3_hot, > > so acpi_pm_device_sleep_state() returns D2 as the target state, where it > > would return D3(cold) before the commit in question. > > > > To fix the regression, we'd need to reverse the current initial value of > > the d3cold_allowed flag so that it is set to "true" by default and only > > set to "false" for devices where we suspect there may be problems with > > D3_cold (like PCI Express ports). > > Good. May I also request a few lines describing d3cold_allowed in e.g > Documentation/ABI/testing/sysfs-bus-pci? I must admit that I thought > that was the policy for any new sysfs file, but it seems that is only > in the USB subsystem? > > Anyway, I believe it ought to be a requirement. If we are meant to > tweak some knob, then we must known how and when to do so. If not, then > why add it in the first place? Yes. I should have added the ABI document. Will write a patch for that. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 20:02 ` Rafael J. Wysocki 2012-07-25 22:36 ` Bjørn Mork @ 2012-07-26 2:38 ` Huang Ying 1 sibling, 0 replies; 89+ messages in thread From: Huang Ying @ 2012-07-26 2:38 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Hi, Rafael, On Wed, 2012-07-25 at 22:02 +0200, Rafael J. Wysocki wrote: > On Wednesday, July 25, 2012, Bjørn Mork wrote: > > huang ying <huang.ying.caritas@gmail.com> writes: > > > > > Hi, Bjorn, > > > > > > Thank you very much for your detailed information. > > > > > > On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: > > >> Huang Ying <ying.huang@intel.com> writes: > > >>> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: > > >>>> Enabling autosuspend for USB causes hotplug failure in the current > > >>>> linux-next. Newly plugged devices are not detected at all until the > > >>>> port/controller is manually powered on by writing "on" to power/control. > > >>>> Testing is pretty simple: > > >>>> > > >>>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done > > >>> > > >>> Have you done: > > >>> > > >>> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done > > >>> > > >>> ? > > >>> > > >>> If not, the pci device will not be suspended at all. > > >> > > >> Yes, sorry for missing that. I had it automatically enabled. Yes, > > >> autosuspend for the PCI device and all child devices must be enabled for > > >> the device to be suspended at all, of course. > > >> > > >>>> 2) wait for the controllers to suspend > > >>>> 3) plugin a new USB device > > >>> > > >>> After plugin the new USB device, is there anything in dmesg? > > >> > > >> No. Absolutely nothing, so the USB devices is not enumerated. Another > > >> indication of the same: Plugging a device like an Android phone, which > > >> normally detects being connected to a host and presents a device type > > >> menu to the user, results in the charging LED lighting up but no menu. > > >> > > >> > > >> Trying to show the sequence of events: > > >> > > >> 1) the controllers are suspended: > > >> > > >> Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > > >> Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > > >> Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > > >> Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 > > >> Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 > > > > > > Here uhci controller is put into D2 > > > > > > [snip] > > >> > > >> Doing the same with commit 448bd857d reverted: > > >> > > >> > > >> 1) the controllers are suspended (to state D3? instead of D2?): > > >> > > >> Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 > > >> Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 > > >> Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 > > >> Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 > > >> Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 > > > > > > With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). > > > > > > And the uhci controller on your system may not work properly under D2 > > > state, while OK in D3 state, and the commit will make uhci controller > > > choose D2 instead of D3. > > > > > > Please try following command line before testing. > > > > > > for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done > > > > That made it work. The USB controllers ended up in D4 though: > > > > Jul 25 15:52:33 nemi kernel: [ 152.753280] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D0 > > Jul 25 15:52:33 nemi kernel: [ 152.753453] uhci_hcd 0000:00:1a.0: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.753619] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D4 > > Jul 25 15:52:33 nemi kernel: [ 152.753875] uhci_hcd 0000:00:1a.1: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.754153] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D0 > > Jul 25 15:52:33 nemi kernel: [ 152.754279] uhci_hcd 0000:00:1a.2: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.754432] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D4 > > Jul 25 15:52:33 nemi kernel: [ 152.754668] ehci_hcd 0000:00:1a.7: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.768089] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > > Jul 25 15:52:33 nemi kernel: [ 152.768573] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D0 > > Jul 25 15:52:33 nemi kernel: [ 152.768726] uhci_hcd 0000:00:1d.0: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.768891] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D4 > > Jul 25 15:52:33 nemi kernel: [ 152.769144] uhci_hcd 0000:00:1d.1: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.769530] uhci_hcd 0000:00:1d.2: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.769902] ehci_hcd 0000:00:1d.7: setting latency timer to 64 > > Jul 25 15:52:33 nemi kernel: [ 152.784189] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > > > > > > was that expected? Anyway, waking up the controller from this state by > > plugging a USB device works, so it's a perfectly OK workaround. Is this > > something that could/should be implemented as a system specific quirk, > > or is the problem more generic? Even if it is a ACPI implementation > > issue I would expect it to be common to a number of Lenovo laptops of > > the same generation as mine (~2008). > > > > > And please provide the output of the following command line. > > > > > > acpidump > > > > Attached. Thanks a lot for all your help debugging this issue. > > This is not really necessary. The problem is the change of behavior I was > worried about some time ago. > > Namely, the device in question apparently doesn't support ACPI D3_hot, > so acpi_pm_device_sleep_state() returns D2 as the target state, where it > would return D3(cold) before the commit in question. > > To fix the regression, we'd need to reverse the current initial value of > the d3cold_allowed flag so that it is set to "true" by default and only > set to "false" for devices where we suspect there may be problems with > D3_cold (like PCI Express ports). Yes. This is a good way to fix this issue and keep original behavior for most devices. I will work out a fix. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-25 13:58 ` Bjørn Mork 2012-07-25 18:56 ` Rafael J. Wysocki 2012-07-25 20:02 ` Rafael J. Wysocki @ 2012-07-26 8:54 ` Huang Ying 2012-07-26 10:35 ` Bjørn Mork 2 siblings, 1 reply; 89+ messages in thread From: Huang Ying @ 2012-07-26 8:54 UTC (permalink / raw) To: Bjørn Mork Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Wed, 2012-07-25 at 15:58 +0200, Bjørn Mork wrote: > huang ying <huang.ying.caritas@gmail.com> writes: > > > Hi, Bjorn, > > > > Thank you very much for your detailed information. > > > > On Wed, Jul 25, 2012 at 5:58 PM, Bjørn Mork <bjorn@mork.no> wrote: > >> Huang Ying <ying.huang@intel.com> writes: > >>> On Wed, 2012-07-25 at 06:08 +0200, Bjørn Mork wrote: > >>>> Enabling autosuspend for USB causes hotplug failure in the current > >>>> linux-next. Newly plugged devices are not detected at all until the > >>>> port/controller is manually powered on by writing "on" to power/control. > >>>> Testing is pretty simple: > >>>> > >>>> 1) for f in /sys/bus/usb/devices/*/power/control; do echo auto > $f; done > >>> > >>> Have you done: > >>> > >>> for f in /sys/bus/pci/devices/*/power/confol; do echo auto > $f; done > >>> > >>> ? > >>> > >>> If not, the pci device will not be suspended at all. > >> > >> Yes, sorry for missing that. I had it automatically enabled. Yes, > >> autosuspend for the PCI device and all child devices must be enabled for > >> the device to be suspended at all, of course. > >> > >>>> 2) wait for the controllers to suspend > >>>> 3) plugin a new USB device > >>> > >>> After plugin the new USB device, is there anything in dmesg? > >> > >> No. Absolutely nothing, so the USB devices is not enumerated. Another > >> indication of the same: Plugging a device like an Android phone, which > >> normally detects being connected to a host and presents a device type > >> menu to the user, results in the charging LED lighting up but no menu. > >> > >> > >> Trying to show the sequence of events: > >> > >> 1) the controllers are suspended: > >> > >> Jul 25 11:27:12 nemi kernel: [ 38.962792] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > >> Jul 25 11:27:12 nemi kernel: [ 39.006718] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.808471] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824123] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D2 > >> Jul 25 11:27:15 nemi kernel: [ 41.824194] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D2 > > > > Here uhci controller is put into D2 > > > > [snip] > >> > >> Doing the same with commit 448bd857d reverted: > >> > >> > >> 1) the controllers are suspended (to state D3? instead of D2?): > >> > >> Jul 25 11:34:01 nemi kernel: [ 37.064955] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D3 > >> Jul 25 11:34:01 nemi kernel: [ 37.106586] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.808329] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840054] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D3 > >> Jul 25 11:34:04 nemi kernel: [ 39.840068] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D3 > > > > With commit reverted, the uhci_controller is put into D3 (ACPI D3cold). > > > > And the uhci controller on your system may not work properly under D2 > > state, while OK in D3 state, and the commit will make uhci controller > > choose D2 instead of D3. > > > > Please try following command line before testing. > > > > for f in /sys/bus/pci/devices/*/d3cold_allowed; do echo 1 > $f; done > > That made it work. The USB controllers ended up in D4 though: > > Jul 25 15:52:33 nemi kernel: [ 152.753280] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.753453] uhci_hcd 0000:00:1a.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.753619] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.753875] uhci_hcd 0000:00:1a.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754153] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.754279] uhci_hcd 0000:00:1a.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.754432] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.754668] ehci_hcd 0000:00:1a.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768089] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.768573] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D0 > Jul 25 15:52:33 nemi kernel: [ 152.768726] uhci_hcd 0000:00:1d.0: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.768891] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D4 > Jul 25 15:52:33 nemi kernel: [ 152.769144] uhci_hcd 0000:00:1d.1: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769530] uhci_hcd 0000:00:1d.2: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.769902] ehci_hcd 0000:00:1d.7: setting latency timer to 64 > Jul 25 15:52:33 nemi kernel: [ 152.784189] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > > > was that expected? Anyway, waking up the controller from this state by > plugging a USB device works, so it's a perfectly OK workaround. Is this > something that could/should be implemented as a system specific quirk, > or is the problem more generic? Even if it is a ACPI implementation > issue I would expect it to be common to a number of Lenovo laptops of > the same generation as mine (~2008). > > > And please provide the output of the following command line. > > > > acpidump > > Attached. Thanks a lot for all your help debugging this issue. Do you have time to try the below patch? Best Regards, Huang Ying Subject: [BUGFIX] PCI/PM: enable D3/D3cold by default for most devices This patch fixes the following bug: http://marc.info/?l=linux-usb&m=134318961120825&w=2 Originally, device lower power states include D1, D2, D3. After that, D3 is further divided into D3hot and D3cold. To support both scenario safely, original D3 is mapped to D3cold. When adding D3cold support, because worry about some device may have broken D3cold support, D3cold is disabled by default. This disable D3 on original platform too. But some original platform may only have working D3, but no working D1, D2. The root cause of the above bug is it too. To deal with this, this patch enables D3/D3cold by default for most devices. This restores the original behavior. For some devices that suspected to have broken D3cold support, such as PCIe port, D3cold is disabled by default. Signed-off-by: Huang Ying <ying.huang@intel.com> --- drivers/pci/pci.c | 1 + drivers/pci/pcie/portdrv_pci.c | 5 +++++ 2 files changed, 6 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1941,6 +1941,7 @@ void pci_pm_init(struct pci_dev *dev) dev->pm_cap = pm; dev->d3_delay = PCI_PM_D3_WAIT; dev->d3cold_delay = PCI_PM_D3COLD_WAIT; + dev->d3cold_allowed = true; dev->d1_support = false; dev->d2_support = false; --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -200,6 +200,11 @@ static int __devinit pcie_portdrv_probe( return status; pci_save_state(dev); + /* + * D3cold may not work properly on some PCIe port, so disable + * it by default. + */ + dev->d3cold_allowed = false; if (!pci_match_id(port_runtime_pm_black_list, dev)) pm_runtime_put_noidle(&dev->dev); ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 8:54 ` Huang Ying @ 2012-07-26 10:35 ` Bjørn Mork 2012-07-26 11:02 ` Bjørn Mork ` (2 more replies) 0 siblings, 3 replies; 89+ messages in thread From: Bjørn Mork @ 2012-07-26 10:35 UTC (permalink / raw) To: Huang Ying Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Huang Ying <ying.huang@intel.com> writes: > Do you have time to try the below patch? Sure. Looks OK wrt the USB problems, but may cause problems with the PCIe WiFi card. Unless those are related to other changes in -next. Anyway, for I applied your patch on top of next-20120724 for consistency (still without Rafael print fix, so we get the D4 below). This results in different stats for the uhci_hcd and ehci_hcd: Jul 26 12:13:42 nemi kernel: [ 72.820305] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 Jul 26 12:13:42 nemi kernel: [ 72.835101] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 Jul 26 12:13:44 nemi kernel: [ 74.808770] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 Jul 26 12:13:44 nemi kernel: [ 74.840293] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 Jul 26 12:13:44 nemi kernel: [ 74.840326] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 I assume that is expected, based on the lspci output I posted earlier. Overall I get a nice mix of allowed/disallowed: nemi:/home/bjorn# grep . /sys/bus/pci/devices/*/d3cold_allowed /sys/bus/pci/devices/0000:00:00.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:02.0/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:02.1/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:03.0/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:19.0/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:1a.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1a.1/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1a.2/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1a.7/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:1b.0/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:1c.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1c.1/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1d.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1d.1/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1d.2/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1d.7/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:1e.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1f.0/d3cold_allowed:0 /sys/bus/pci/devices/0000:00:1f.2/d3cold_allowed:1 /sys/bus/pci/devices/0000:00:1f.3/d3cold_allowed:0 /sys/bus/pci/devices/0000:03:00.0/d3cold_allowed:1 USB hotplugging seems to work fine with this. But attempting to unload/reload the wifi drivers resulted in this: Jul 26 12:20:43 nemi kernel: [ 493.812266] iwlwifi 0000:03:00.0: Refused to change power state, currently in D3 Jul 26 12:20:43 nemi kernel: [ 493.812331] iwlwifi 0000:03:00.0: pci_resource_len = 0x00002000 Jul 26 12:20:43 nemi kernel: [ 493.812335] iwlwifi 0000:03:00.0: pci_resource_base = ffffc900055a4000 Jul 26 12:20:43 nemi kernel: [ 493.812339] iwlwifi 0000:03:00.0: HW Revision ID = 0x0 Jul 26 12:20:43 nemi kernel: [ 493.812350] iwlwifi 0000:03:00.0: pci_enable_msi failed(0Xffffffea) Jul 26 12:20:43 nemi kernel: [ 493.812377] driver: '0000:03:00.0': driver_bound: bound to device 'iwlwifi' Jul 26 12:20:43 nemi kernel: [ 493.812385] bus: 'pci': really_probe: bound device 0000:03:00.0 to driver iwlwifi Jul 26 12:20:43 nemi kernel: [ 493.813634] iwldvm: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree: Jul 26 12:20:43 nemi kernel: [ 493.813637] iwldvm: Copyright(c) 2003-2012 Intel Corporation Jul 26 12:20:43 nemi kernel: [ 493.813912] device: '0000:03:00.0': device_add Jul 26 12:20:43 nemi kernel: [ 493.813939] PM: Adding info for No Bus:0000:03:00.0 Jul 26 12:20:43 nemi kernel: [ 493.813947] firmware 0000:03:00.0: firmware: requesting iwlwifi-5000-5.ucode Jul 26 12:20:43 nemi kernel: [ 493.827551] PM: Removing info for No Bus:0000:03:00.0 Jul 26 12:20:43 nemi kernel: [ 493.827615] iwlwifi 0000:03:00.0: loaded firmware version 8.83.5.1 build 33692 Jul 26 12:20:43 nemi kernel: [ 493.828170] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUG disabled Jul 26 12:20:43 nemi kernel: [ 493.828175] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUGFS disabled Jul 26 12:20:43 nemi kernel: [ 493.828178] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TRACING disabled Jul 26 12:20:43 nemi kernel: [ 493.828182] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TESTMODE disabled Jul 26 12:20:43 nemi kernel: [ 493.828185] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_P2P disabled Jul 26 12:20:43 nemi kernel: [ 493.828190] iwlwifi 0000:03:00.0: Detected Intel(R) Ultimate N WiFi Link 5300 AGN, REV=0xFFFFFFFF Jul 26 12:20:43 nemi kernel: [ 493.828218] iwlwifi 0000:03:00.0: L1 Enabled; Disabling L0S Jul 26 12:20:43 nemi kernel: [ 493.832013] ------------[ cut here ]------------ Jul 26 12:20:43 nemi kernel: [ 493.832013] WARNING: at drivers/net/wireless/iwlwifi/iwl-io.c:150 iwl_grab_nic_access+0x47/0x54 [iwlwifi]() Jul 26 12:20:43 nemi kernel: [ 493.832013] Hardware name: 2776LEG Jul 26 12:20:43 nemi kernel: [ 493.832013] Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff) Jul 26 12:20:43 nemi kernel: [ 493.832013] Modules linked in: iwldvm iwlwifi mac80211 cfg80211 cpufreq_userspace cpufreq_stats cpufreq_conservative cpufreq_powersave xt_multiport xt_hl ip6table_filter iptable_filter ip_tables ip6_tables x_tables rfcomm bnep binfmt_misc fuse nfsd nfs lockd fscache auth_rpcgss nfs_acl sunrpc 8021q garp stp llc tun ext2 loop snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm thinkpad_acpi snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device arc4 snd i915 coretemp kvm_intel qcserial drm_kms_helper usb_wwan acpi_cpufreq drm psmouse lpc_ich i2c_algo_bit soundcore usbserial qmi_wwan usbnet mii cdc_wdm kvm microcode btusb evdev bluetooth i2c_i801 serio_raw mfd_core rfkill mei snd_page_alloc crc16 i2c_core battery nvram ac video wmi mperf processor button ext3 mbcache jbd sha256_generic ablk_helper cryptd aes_x86_64 aes_generic cbc dm_crypt dm_mod nbd sd_mod crc_t10dif sr_mod cdrom uhci_hcd ahci libahci libata ehci_hc Jul 26 12:20:43 nemi kernel: d scsi_mod thermal thermal_sys usbcore usb_common e1000e [last unloaded: cfg80211] Jul 26 12:20:43 nemi kernel: [ 493.832013] Pid: 200, comm: kworker/0:2 Not tainted 3.5.0-rc2-next-20120724+ #23 Jul 26 12:20:43 nemi kernel: [ 493.832013] Call Trace: Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8103d0fd>] ? warn_slowpath_common+0x78/0x8c Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8103d1af>] ? warn_slowpath_fmt+0x45/0x4a Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03822be>] ? iwl_grab_nic_access+0x47/0x54 [iwlwifi] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa0382590>] ? iwl_write_prph+0x29/0x56 [iwlwifi] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03882cb>] ? iwl_apm_init+0x13a/0x16b [iwlwifi] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03883fd>] ? iwl_trans_pcie_start_hw+0x101/0x15b [iwlwifi] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa026aa5b>] ? iwl_op_mode_dvm_start+0x246/0x96a [iwldvm] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03835d1>] ? iwl_ucode_callback+0x9e5/0xad8 [iwlwifi] Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff812793c2>] ? _request_firmware_prepare+0x1e2/0x1e2 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81279471>] ? request_firmware_work_func+0xaf/0xe4 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054dea>] ? process_one_work+0x1ff/0x311 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff810550f7>] ? worker_thread+0x1fb/0x2fb Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054efc>] ? process_one_work+0x311/0x311 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054efc>] ? process_one_work+0x311/0x311 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff810588fd>] ? kthread+0x81/0x89 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff813703c4>] ? kernel_thread_helper+0x4/0x10 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8105887c>] ? kthread_freezable_should_stop+0x53/0x53 Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff813703c0>] ? gs_change+0x13/0x13 Jul 26 12:20:43 nemi kernel: [ 493.832013] ---[ end trace fcaaf916dd43b7ca ]--- Jul 26 12:20:43 nemi kernel: [ 493.864785] iwlwifi 0000:03:00.0: bad EEPROM/OTP signature, type=OTP, EEPROM_GP=0x00000007 Jul 26 12:20:43 nemi kernel: [ 493.864791] iwlwifi 0000:03:00.0: EEPROM not found, EEPROM_GP=0xffffffff Jul 26 12:20:43 nemi kernel: [ 493.864795] iwlwifi 0000:03:00.0: Unable to init EEPROM That does not look good... The bridge and WiFi devices power status at this point is: bjorn@nemi:~$ grep . /sys/bus/pci/devices/0000:00:1c.1/power/* /sys/bus/pci/devices/0000:00:1c.1/power/async:enabled grep: /sys/bus/pci/devices/0000:00:1c.1/power/autosuspend_delay_ms: Input/output error /sys/bus/pci/devices/0000:00:1c.1/power/control:auto /sys/bus/pci/devices/0000:00:1c.1/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:00:1c.1/power/runtime_active_time:390576 /sys/bus/pci/devices/0000:00:1c.1/power/runtime_enabled:enabled /sys/bus/pci/devices/0000:00:1c.1/power/runtime_status:suspended /sys/bus/pci/devices/0000:00:1c.1/power/runtime_suspended_time:697004 /sys/bus/pci/devices/0000:00:1c.1/power/runtime_usage:0 /sys/bus/pci/devices/0000:00:1c.1/power/wakeup:disabled bjorn@nemi:~$ grep . /sys/bus/pci/devices/0000:03:00.0/power/* /sys/bus/pci/devices/0000:03:00.0/power/async:enabled grep: /sys/bus/pci/devices/0000:03:00.0/power/autosuspend_delay_ms: Input/output error /sys/bus/pci/devices/0000:03:00.0/power/control:auto /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_kids:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_time:0 /sys/bus/pci/devices/0000:03:00.0/power/runtime_enabled:disabled /sys/bus/pci/devices/0000:03:00.0/power/runtime_status:unsupported /sys/bus/pci/devices/0000:03:00.0/power/runtime_suspended_time:70220 /sys/bus/pci/devices/0000:03:00.0/power/runtime_usage:0 /sys/bus/pci/devices/0000:03:00.0/power/wakeup:disabled I don't really understand the last one. How can suspended_time > 0 when status is unsupported and autosuspend is disabled? Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 10:35 ` Bjørn Mork @ 2012-07-26 11:02 ` Bjørn Mork 2012-07-26 12:04 ` Bjørn Mork 2012-07-26 15:03 ` Alan Stern 2012-07-27 5:35 ` Huang Ying 2 siblings, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-26 11:02 UTC (permalink / raw) To: Huang Ying Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Bjørn Mork <bjorn@mork.no> writes: > > Jul 26 12:20:43 nemi kernel: [ 493.812266] iwlwifi 0000:03:00.0: Refused to change power state, currently in D3 > Jul 26 12:20:43 nemi kernel: [ 493.812331] iwlwifi 0000:03:00.0: pci_resource_len = 0x00002000 > Jul 26 12:20:43 nemi kernel: [ 493.812335] iwlwifi 0000:03:00.0: pci_resource_base = ffffc900055a4000 > Jul 26 12:20:43 nemi kernel: [ 493.812339] iwlwifi 0000:03:00.0: HW Revision ID = 0x0 > Jul 26 12:20:43 nemi kernel: [ 493.812350] iwlwifi 0000:03:00.0: pci_enable_msi failed(0Xffffffea) [..] > Jul 26 12:20:43 nemi kernel: [ 493.832013] ---[ end trace fcaaf916dd43b7ca ]--- > Jul 26 12:20:43 nemi kernel: [ 493.864785] iwlwifi 0000:03:00.0: bad EEPROM/OTP signature, type=OTP, EEPROM_GP=0x00000007 > Jul 26 12:20:43 nemi kernel: [ 493.864791] iwlwifi 0000:03:00.0: EEPROM not found, EEPROM_GP=0xffffffff > Jul 26 12:20:43 nemi kernel: [ 493.864795] iwlwifi 0000:03:00.0: Unable to init EEPROM Doing echo on >/sys/bus/pci/devices/0000:00:1c.1/power/control to force the brigde on and then unload/reload driver "fixes" this issue. But I believe it is safe to say that this does not work as it should. I assume the bridge should have been automatically woken up first here? And why the odd autosuspend output? The Wifi device and bridge PM caps look compatible to my untrained eye, and should make both D3hot and D3cold supported ?: Capabilities: [c8] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 11:02 ` Bjørn Mork @ 2012-07-26 12:04 ` Bjørn Mork 0 siblings, 0 replies; 89+ messages in thread From: Bjørn Mork @ 2012-07-26 12:04 UTC (permalink / raw) To: Huang Ying Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Bjørn Mork <bjorn@mork.no> writes: > Capabilities: [c8] Power Management version 3 > Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) > Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- > > Capabilities: [a0] Power Management version 2 > Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) > Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- > That was from the previous captured lspci output. But I assume you might be interested in the state when the driver fails. The default with your newest patch is to allow d3cold for the WiFi device but disallow it for the bridge (PCIe port). Which I guess is the intention based on the patch description. This seems to work. The PCIe port ends up in D3: nemi:/home/bjorn# lspci -vvnns 00:1c.1 00:1c.1 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 [8086:2942] (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 00003000-00003fff Memory behind bridge: f0500000-f05fffff Prefetchable memory behind bridge: 00000000c0400000-00000000c05fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #2, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <256ns, L1 <4us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Slot #1, PowerLimit 6.500W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet+ CmdCplt+ HPIrq+ LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState+ RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+ CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 4143 Capabilities: [90] Subsystem: Lenovo Device [17aa:20f3] Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed+ WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01 Status: NegoPending- InProgress- Capabilities: [180 v1] Root Complex Link Desc: PortNumber=02 ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: pcieport Attempting to read the WiFi device config at this point is futile: nemi:/home/bjorn# lspci -vvnns 03:00.0 03:00.0 Network controller [0280]: Intel Corporation Ultimate N WiFi Link 5300 [8086:4236] (rev ff) (prog-if ff) !!! Unknown header type 7f Does that work as expected BTW? Would be nice if any attempt to read config would wake the brigde to allow it, would it not? I have absolutely no idea whether that's is achievable.. But any attempt to load a driver for the WiFi device should most definitely wake the bridge. But it does not: nemi:/home/bjorn# modprobe iwldvm; lspci -vvnns 00:1c.1 00:1c.1 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 [8086:2942] (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 00003000-00003fff Memory behind bridge: f0500000-f05fffff Prefetchable memory behind bridge: 00000000c0400000-00000000c05fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #2, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <256ns, L1 <4us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Slot #1, PowerLimit 6.500W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet+ CmdCplt+ HPIrq+ LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState+ RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+ CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 4143 Capabilities: [90] Subsystem: Lenovo Device [17aa:20f3] Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed+ WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01 Status: NegoPending- InProgress- Capabilities: [180 v1] Root Complex Link Desc: PortNumber=02 ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: pcieport I have tried all 4 combinations of d3cold_allowed for these 2 devices, but none of them make any difference. The default with your patches is to disallow it for the PCIe port. One strange issue is that the PCIe port goes into the same stat even if I set d3cold_allowed to 1: Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Should't the status then be "D4" or "D3cold" or whatever lspci will call it? At least different? The d3cold_allowed setting does not seem to change anything for this port. Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 10:35 ` Bjørn Mork 2012-07-26 11:02 ` Bjørn Mork @ 2012-07-26 15:03 ` Alan Stern 2012-07-26 16:24 ` Bjørn Mork 2012-07-27 5:35 ` Huang Ying 2 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-26 15:03 UTC (permalink / raw) To: Bjørn Mork Cc: Huang Ying, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Thu, 26 Jul 2012, Bjørn Mork wrote: > Huang Ying <ying.huang@intel.com> writes: > > > Do you have time to try the below patch? > > Sure. Looks OK wrt the USB problems, but may cause problems with the > PCIe WiFi card. Unless those are related to other changes in -next. > > Anyway, for I applied your patch on top of next-20120724 for > consistency (still without Rafael print fix, so we get the D4 below). > This results in different stats for the uhci_hcd and ehci_hcd: > > > Jul 26 12:13:42 nemi kernel: [ 72.820305] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > Jul 26 12:13:42 nemi kernel: [ 72.835101] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > Jul 26 12:13:44 nemi kernel: [ 74.808770] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > Jul 26 12:13:44 nemi kernel: [ 74.840293] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > Jul 26 12:13:44 nemi kernel: [ 74.840326] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > > I assume that is expected, based on the lspci output I posted earlier. > Overall I get a nice mix of allowed/disallowed: ... > USB hotplugging seems to work fine with this. Don't be too sure. Have you tested to see if it still works after doing "rmmod ehci-hcd"? So far you have tested the EHCI controllers, but have you tested the UHCI controllers? Unloading ehci-hcd will force them to be used. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 15:03 ` Alan Stern @ 2012-07-26 16:24 ` Bjørn Mork 0 siblings, 0 replies; 89+ messages in thread From: Bjørn Mork @ 2012-07-26 16:24 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb Alan Stern <stern@rowland.harvard.edu> writes: >> USB hotplugging seems to work fine with this. > > Don't be too sure. Have you tested to see if it still works after > doing "rmmod ehci-hcd"? > > So far you have tested the EHCI controllers, but have you tested the > UHCI controllers? Unloading ehci-hcd will force them to be used. Good point. Now tested and seems to work. But I'd appreciate it if someone else were able to doublecheck my results. I am juggling with a number of settings and could easily mess up something, invalidating the tests. I believe the issue should be present in lots of systems, isn't that correct? Any GM45 based laptop should do as a test bench, and maybe others too. The WiFi issues I had also indicates that these changes should be tested on as many different systems as possible. Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-26 10:35 ` Bjørn Mork 2012-07-26 11:02 ` Bjørn Mork 2012-07-26 15:03 ` Alan Stern @ 2012-07-27 5:35 ` Huang Ying 2012-07-27 9:11 ` Bjørn Mork 2012-07-27 15:03 ` Alan Stern 2 siblings, 2 replies; 89+ messages in thread From: Huang Ying @ 2012-07-27 5:35 UTC (permalink / raw) To: Bjørn Mork Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Thu, 2012-07-26 at 12:35 +0200, Bjørn Mork wrote: > Huang Ying <ying.huang@intel.com> writes: > > > Do you have time to try the below patch? > > Sure. Looks OK wrt the USB problems, but may cause problems with the > PCIe WiFi card. Unless those are related to other changes in -next. > > Anyway, for I applied your patch on top of next-20120724 for > consistency (still without Rafael print fix, so we get the D4 below). > This results in different stats for the uhci_hcd and ehci_hcd: > > > Jul 26 12:13:42 nemi kernel: [ 72.820305] uhci_hcd 0000:00:1a.2: power state changed by ACPI to D2 > Jul 26 12:13:42 nemi kernel: [ 72.835101] uhci_hcd 0000:00:1d.0: power state changed by ACPI to D2 > Jul 26 12:13:44 nemi kernel: [ 74.808770] uhci_hcd 0000:00:1a.0: power state changed by ACPI to D2 > Jul 26 12:13:44 nemi kernel: [ 74.840293] ehci_hcd 0000:00:1d.7: power state changed by ACPI to D4 > Jul 26 12:13:44 nemi kernel: [ 74.840326] ehci_hcd 0000:00:1a.7: power state changed by ACPI to D4 > > I assume that is expected, based on the lspci output I posted earlier. > Overall I get a nice mix of allowed/disallowed: > > > > nemi:/home/bjorn# grep . /sys/bus/pci/devices/*/d3cold_allowed > /sys/bus/pci/devices/0000:00:00.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:02.0/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:02.1/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:03.0/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:19.0/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:1a.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1a.1/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1a.2/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1a.7/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:1b.0/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:1c.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1c.1/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1d.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1d.1/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1d.2/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1d.7/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:1e.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1f.0/d3cold_allowed:0 > /sys/bus/pci/devices/0000:00:1f.2/d3cold_allowed:1 > /sys/bus/pci/devices/0000:00:1f.3/d3cold_allowed:0 > /sys/bus/pci/devices/0000:03:00.0/d3cold_allowed:1 > > > USB hotplugging seems to work fine with this. But attempting to > unload/reload the wifi drivers resulted in this: > > > > > Jul 26 12:20:43 nemi kernel: [ 493.812266] iwlwifi 0000:03:00.0: Refused to change power state, currently in D3 I think this is because the parent bridge (PCIe port) is in lower power state. So write to PM registers of child device takes no effect. > Jul 26 12:20:43 nemi kernel: [ 493.812331] iwlwifi 0000:03:00.0: pci_resource_len = 0x00002000 > Jul 26 12:20:43 nemi kernel: [ 493.812335] iwlwifi 0000:03:00.0: pci_resource_base = ffffc900055a4000 > Jul 26 12:20:43 nemi kernel: [ 493.812339] iwlwifi 0000:03:00.0: HW Revision ID = 0x0 > Jul 26 12:20:43 nemi kernel: [ 493.812350] iwlwifi 0000:03:00.0: pci_enable_msi failed(0Xffffffea) > Jul 26 12:20:43 nemi kernel: [ 493.812377] driver: '0000:03:00.0': driver_bound: bound to device 'iwlwifi' > Jul 26 12:20:43 nemi kernel: [ 493.812385] bus: 'pci': really_probe: bound device 0000:03:00.0 to driver iwlwifi > Jul 26 12:20:43 nemi kernel: [ 493.813634] iwldvm: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree: > Jul 26 12:20:43 nemi kernel: [ 493.813637] iwldvm: Copyright(c) 2003-2012 Intel Corporation > Jul 26 12:20:43 nemi kernel: [ 493.813912] device: '0000:03:00.0': device_add > Jul 26 12:20:43 nemi kernel: [ 493.813939] PM: Adding info for No Bus:0000:03:00.0 > Jul 26 12:20:43 nemi kernel: [ 493.813947] firmware 0000:03:00.0: firmware: requesting iwlwifi-5000-5.ucode > Jul 26 12:20:43 nemi kernel: [ 493.827551] PM: Removing info for No Bus:0000:03:00.0 > Jul 26 12:20:43 nemi kernel: [ 493.827615] iwlwifi 0000:03:00.0: loaded firmware version 8.83.5.1 build 33692 > Jul 26 12:20:43 nemi kernel: [ 493.828170] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUG disabled > Jul 26 12:20:43 nemi kernel: [ 493.828175] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUGFS disabled > Jul 26 12:20:43 nemi kernel: [ 493.828178] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TRACING disabled > Jul 26 12:20:43 nemi kernel: [ 493.828182] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TESTMODE disabled > Jul 26 12:20:43 nemi kernel: [ 493.828185] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_P2P disabled > Jul 26 12:20:43 nemi kernel: [ 493.828190] iwlwifi 0000:03:00.0: Detected Intel(R) Ultimate N WiFi Link 5300 AGN, REV=0xFFFFFFFF > Jul 26 12:20:43 nemi kernel: [ 493.828218] iwlwifi 0000:03:00.0: L1 Enabled; Disabling L0S > Jul 26 12:20:43 nemi kernel: [ 493.832013] ------------[ cut here ]------------ > Jul 26 12:20:43 nemi kernel: [ 493.832013] WARNING: at drivers/net/wireless/iwlwifi/iwl-io.c:150 iwl_grab_nic_access+0x47/0x54 [iwlwifi]() > Jul 26 12:20:43 nemi kernel: [ 493.832013] Hardware name: 2776LEG > Jul 26 12:20:43 nemi kernel: [ 493.832013] Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff) > Jul 26 12:20:43 nemi kernel: [ 493.832013] Modules linked in: iwldvm iwlwifi mac80211 cfg80211 cpufreq_userspace cpufreq_stats cpufreq_conservative cpufreq_powersave xt_multiport xt_hl ip6table_filter iptable_filter ip_tables ip6_tables x_tables rfcomm bnep binfmt_misc fuse nfsd nfs lockd fscache auth_rpcgss nfs_acl sunrpc 8021q garp stp llc tun ext2 loop snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm thinkpad_acpi snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device arc4 snd i915 coretemp kvm_intel qcserial drm_kms_helper usb_wwan acpi_cpufreq drm psmouse lpc_ich i2c_algo_bit soundcore usbserial qmi_wwan usbnet mii cdc_wdm kvm microcode btusb evdev bluetooth i2c_i801 serio_raw mfd_core rfkill mei snd_page_alloc crc16 i2c_core battery nvram ac video wmi mperf processor button ext3 mbcache jbd sha256_generic ablk_helper cryptd aes_x86_64 aes_generic cbc dm_crypt dm_mod nbd sd_mod crc_t10dif sr_mod cdrom uhci_hcd ahci libahci libata ehci_hc > Jul 26 12:20:43 nemi kernel: d scsi_mod thermal thermal_sys usbcore usb_common e1000e [last unloaded: cfg80211] > Jul 26 12:20:43 nemi kernel: [ 493.832013] Pid: 200, comm: kworker/0:2 Not tainted 3.5.0-rc2-next-20120724+ #23 > Jul 26 12:20:43 nemi kernel: [ 493.832013] Call Trace: > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8103d0fd>] ? warn_slowpath_common+0x78/0x8c > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8103d1af>] ? warn_slowpath_fmt+0x45/0x4a > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03822be>] ? iwl_grab_nic_access+0x47/0x54 [iwlwifi] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa0382590>] ? iwl_write_prph+0x29/0x56 [iwlwifi] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03882cb>] ? iwl_apm_init+0x13a/0x16b [iwlwifi] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03883fd>] ? iwl_trans_pcie_start_hw+0x101/0x15b [iwlwifi] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa026aa5b>] ? iwl_op_mode_dvm_start+0x246/0x96a [iwldvm] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffffa03835d1>] ? iwl_ucode_callback+0x9e5/0xad8 [iwlwifi] > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff812793c2>] ? _request_firmware_prepare+0x1e2/0x1e2 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81279471>] ? request_firmware_work_func+0xaf/0xe4 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054dea>] ? process_one_work+0x1ff/0x311 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff810550f7>] ? worker_thread+0x1fb/0x2fb > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054efc>] ? process_one_work+0x311/0x311 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff81054efc>] ? process_one_work+0x311/0x311 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff810588fd>] ? kthread+0x81/0x89 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff813703c4>] ? kernel_thread_helper+0x4/0x10 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff8105887c>] ? kthread_freezable_should_stop+0x53/0x53 > Jul 26 12:20:43 nemi kernel: [ 493.832013] [<ffffffff813703c0>] ? gs_change+0x13/0x13 > Jul 26 12:20:43 nemi kernel: [ 493.832013] ---[ end trace fcaaf916dd43b7ca ]--- > Jul 26 12:20:43 nemi kernel: [ 493.864785] iwlwifi 0000:03:00.0: bad EEPROM/OTP signature, type=OTP, EEPROM_GP=0x00000007 > Jul 26 12:20:43 nemi kernel: [ 493.864791] iwlwifi 0000:03:00.0: EEPROM not found, EEPROM_GP=0xffffffff > Jul 26 12:20:43 nemi kernel: [ 493.864795] iwlwifi 0000:03:00.0: Unable to init EEPROM > > > That does not look good... > > The bridge and WiFi devices power status at this point is: > > bjorn@nemi:~$ grep . /sys/bus/pci/devices/0000:00:1c.1/power/* > /sys/bus/pci/devices/0000:00:1c.1/power/async:enabled > grep: /sys/bus/pci/devices/0000:00:1c.1/power/autosuspend_delay_ms: Input/output error > /sys/bus/pci/devices/0000:00:1c.1/power/control:auto > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_active_kids:0 > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_active_time:390576 > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_enabled:enabled > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_status:suspended > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_suspended_time:697004 > /sys/bus/pci/devices/0000:00:1c.1/power/runtime_usage:0 > /sys/bus/pci/devices/0000:00:1c.1/power/wakeup:disabled > > bjorn@nemi:~$ grep . /sys/bus/pci/devices/0000:03:00.0/power/* > /sys/bus/pci/devices/0000:03:00.0/power/async:enabled > grep: /sys/bus/pci/devices/0000:03:00.0/power/autosuspend_delay_ms: Input/output error > /sys/bus/pci/devices/0000:03:00.0/power/control:auto > /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_kids:0 > /sys/bus/pci/devices/0000:03:00.0/power/runtime_active_time:0 > /sys/bus/pci/devices/0000:03:00.0/power/runtime_enabled:disabled > /sys/bus/pci/devices/0000:03:00.0/power/runtime_status:unsupported > /sys/bus/pci/devices/0000:03:00.0/power/runtime_suspended_time:70220 > /sys/bus/pci/devices/0000:03:00.0/power/runtime_usage:0 > /sys/bus/pci/devices/0000:03:00.0/power/wakeup:disabled > > > > I don't really understand the last one. How can suspended_time > 0 when > status is unsupported and autosuspend is disabled? Do you have time to try the following patch? Best Regards, Huang Ying --- drivers/pci/pci-driver.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) { struct drv_dev_and_id *ddi = _ddi; struct device *dev = &ddi->dev->dev; + struct device *parent = dev->parent; int rc; + /* The parent bridge must be in active state when probing */ + if (parent) + pm_runtime_get_sync(parent); /* Unbound PCI devices are always set to disabled and suspended. * During probe, the device is set to enabled and active and the * usage count is incremented. If the driver supports runtime PM, @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev); } + if (parent) + pm_runtime_put(parent); return rc; } ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 5:35 ` Huang Ying @ 2012-07-27 9:11 ` Bjørn Mork 2012-07-30 3:15 ` Huang Ying 2012-07-27 15:03 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-27 9:11 UTC (permalink / raw) To: Huang Ying Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Huang Ying <ying.huang@intel.com> writes: > Do you have time to try the following patch? > > Best Regards, > Huang Ying > > --- > drivers/pci/pci-driver.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > { > struct drv_dev_and_id *ddi = _ddi; > struct device *dev = &ddi->dev->dev; > + struct device *parent = dev->parent; > int rc; > > + /* The parent bridge must be in active state when probing */ > + if (parent) > + pm_runtime_get_sync(parent); > /* Unbound PCI devices are always set to disabled and suspended. > * During probe, the device is set to enabled and active and the > * usage count is incremented. If the driver supports runtime PM, > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > pm_runtime_set_suspended(dev); > pm_runtime_put_noidle(dev); > } > + if (parent) > + pm_runtime_put(parent); > return rc; > } > Yup, that worked in the quick test I just did. lspci reading the device config will still not wake the bridge, but I assume that is intentional? But loading the device driver now wakes both the bridge and the device, so that works. Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 9:11 ` Bjørn Mork @ 2012-07-30 3:15 ` Huang Ying 2012-07-30 8:08 ` Bjørn Mork 2012-07-30 14:19 ` Alan Stern 0 siblings, 2 replies; 89+ messages in thread From: Huang Ying @ 2012-07-30 3:15 UTC (permalink / raw) To: Bjørn Mork Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Fri, 2012-07-27 at 11:11 +0200, Bjørn Mork wrote: > Huang Ying <ying.huang@intel.com> writes: > > > Do you have time to try the following patch? > > > > Best Regards, > > Huang Ying > > > > --- > > drivers/pci/pci-driver.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > --- a/drivers/pci/pci-driver.c > > +++ b/drivers/pci/pci-driver.c > > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > > { > > struct drv_dev_and_id *ddi = _ddi; > > struct device *dev = &ddi->dev->dev; > > + struct device *parent = dev->parent; > > int rc; > > > > + /* The parent bridge must be in active state when probing */ > > + if (parent) > > + pm_runtime_get_sync(parent); > > /* Unbound PCI devices are always set to disabled and suspended. > > * During probe, the device is set to enabled and active and the > > * usage count is incremented. If the driver supports runtime PM, > > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > > pm_runtime_set_suspended(dev); > > pm_runtime_put_noidle(dev); > > } > > + if (parent) > > + pm_runtime_put(parent); > > return rc; > > } > > > > > Yup, that worked in the quick test I just did. > > lspci reading the device config will still not wake the bridge, but I > assume that is intentional? But loading the device driver now wakes > both the bridge and the device, so that works. Do you have time to test the following patch to fix the lspci issue? Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg This patch fixes the following bug: http://marc.info/?l=linux-pci&m=134338059022620&w=2 Where lspci does not work properly if a device and the corresponding parent bridge (such as PCIe port) is suspended. This is because the device configuration space registers will be not accessible if the corresponding parent bridge is suspended. To solve the issue, the bridge/PCIe port connected to the device is put into active state before read/write configuration space registers. To avoid resume/suspend PCIe port for each configuration register read/write, a small delay is added before the PCIe port to go suspended. Reported-by: Bjorn Mork <bjorn@mork.no> Signed-off-by: Huang Ying <ying.huang@intel.com> --- drivers/pci/pci-sysfs.c | 14 ++++++++++++++ drivers/pci/pcie/portdrv_pci.c | 9 +++++++++ 2 files changed, 23 insertions(+) --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -464,6 +464,7 @@ pci_read_config(struct file *filp, struc char *buf, loff_t off, size_t count) { struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj)); + struct device *parent = dev->dev.parent; unsigned int size = 64; loff_t init_off = off; u8 *data = (u8*) buf; @@ -484,6 +485,9 @@ pci_read_config(struct file *filp, struc size = count; } + if (parent) + pm_runtime_get_sync(parent); + if ((off & 1) && size) { u8 val; pci_user_read_config_byte(dev, off, &val); @@ -529,6 +533,9 @@ pci_read_config(struct file *filp, struc --size; } + if (parent) + pm_runtime_put(parent); + return count; } @@ -538,6 +545,7 @@ pci_write_config(struct file* filp, stru char *buf, loff_t off, size_t count) { struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj)); + struct device *parent = dev->dev.parent; unsigned int size = count; loff_t init_off = off; u8 *data = (u8*) buf; @@ -549,6 +557,9 @@ pci_write_config(struct file* filp, stru count = size; } + if (parent) + pm_runtime_get_sync(parent); + if ((off & 1) && size) { pci_user_write_config_byte(dev, off, data[off - init_off]); off++; @@ -587,6 +598,9 @@ pci_write_config(struct file* filp, stru --size; } + if (parent) + pm_runtime_put(parent); + return count; } --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -140,9 +140,17 @@ static int pcie_port_runtime_resume(stru { return 0; } + +static int pcie_port_runtime_idle(struct device *dev) +{ + /* Delay for a short while to prevent too frequent suspend/resume */ + pm_schedule_suspend(dev, 10); + return -EBUSY; +} #else #define pcie_port_runtime_suspend NULL #define pcie_port_runtime_resume NULL +#define pcie_port_runtime_idle NULL #endif static const struct dev_pm_ops pcie_portdrv_pm_ops = { @@ -155,6 +163,7 @@ static const struct dev_pm_ops pcie_port .resume_noirq = pcie_port_resume_noirq, .runtime_suspend = pcie_port_runtime_suspend, .runtime_resume = pcie_port_runtime_resume, + .runtime_idle = pcie_port_runtime_idle, }; #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops) ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 3:15 ` Huang Ying @ 2012-07-30 8:08 ` Bjørn Mork 2012-07-30 13:31 ` huang ying 2012-07-30 14:19 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-30 8:08 UTC (permalink / raw) To: Huang Ying Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern Huang Ying <ying.huang@intel.com> writes: > Do you have time to test the following patch to fix the lspci issue? > > Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg Sure. But keep this going and I will file a request for modular build of the PCI subsystem :-) The patch works fine for me: nemi:/home/bjorn# lspci -t -[0000:00]-+-00.0 +-02.0 +-02.1 +-03.0 +-19.0 +-1a.0 +-1a.1 +-1a.2 +-1a.7 +-1b.0 +-1c.0-[02]-- +-1c.1-[03]----00.0 +-1d.0 +-1d.1 +-1d.2 +-1d.7 +-1e.0-[15]-- +-1f.0 +-1f.2 \-1f.3 nemi:/home/bjorn# lspci -vvnns 1c.1; lspci -vvnns 3:0 00:1c.1 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 [8086:2942] (rev 03) (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 00003000-00003fff Memory behind bridge: f0500000-f05fffff Prefetchable memory behind bridge: 00000000c0400000-00000000c05fffff Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us ExtTag- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #2, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <256ns, L1 <4us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Slot #1, PowerLimit 6.500W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg- Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState+ RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0300c Data: 4143 Capabilities: [90] Subsystem: Lenovo Device [17aa:20f3] Capabilities: [a0] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed+ WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01 Status: NegoPending- InProgress- Capabilities: [180 v1] Root Complex Link Desc: PortNumber=02 ComponentID=02 EltType=Config Link0: Desc: TargetPort=00 TargetComponent=02 AssocRCRB- LinkType=MemMapped LinkValid+ Addr: 00000000fed1c000 Kernel driver in use: pcieport 03:00.0 Network controller [0280]: Intel Corporation Ultimate N WiFi Link 5300 [8086:4236] Subsystem: Intel Corporation Device [8086:1011] Physical Slot: 1 Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 17 Region 0: Memory at f0500000 (64-bit, non-prefetchable) [size=8K] Capabilities: [c8] Power Management version 3 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+ Address: 00000000fee0300c Data: 4183 Capabilities: [e0] Express (v1) Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr+ TransPend- LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <128ns, L1 <32us ClockPM+ Surprise- LLActRep- BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- Capabilities: [100 v1] Advanced Error Reporting UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol- CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn- Capabilities: [140 v1] Device Serial Number 00-16-ea-ff-ff-b3-07-88 Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 8:08 ` Bjørn Mork @ 2012-07-30 13:31 ` huang ying 2012-07-30 16:57 ` Bjørn Mork 0 siblings, 1 reply; 89+ messages in thread From: huang ying @ 2012-07-30 13:31 UTC (permalink / raw) To: Bjørn Mork Cc: Huang Ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Mon, Jul 30, 2012 at 4:08 PM, Bjørn Mork <bjorn@mork.no> wrote: > Huang Ying <ying.huang@intel.com> writes: > >> Do you have time to test the following patch to fix the lspci issue? >> >> Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > > > Sure. But keep this going and I will file a request for modular build > of the PCI subsystem :-) Why? All not so old PC hardware has PCI/PCIe devices. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 13:31 ` huang ying @ 2012-07-30 16:57 ` Bjørn Mork 2012-07-31 0:22 ` Huang Ying 0 siblings, 1 reply; 89+ messages in thread From: Bjørn Mork @ 2012-07-30 16:57 UTC (permalink / raw) To: huang ying Cc: Huang Ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern huang ying <huang.ying.caritas@gmail.com> writes: > On Mon, Jul 30, 2012 at 4:08 PM, Bjørn Mork <bjorn@mork.no> wrote: >> Huang Ying <ying.huang@intel.com> writes: >> >>> Do you have time to test the following patch to fix the lspci issue? >>> >>> Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg >> >> >> Sure. But keep this going and I will file a request for modular build >> of the PCI subsystem :-) > > Why? All not so old PC hardware has PCI/PCIe devices. So that I didn't have to reboot all the time to test your new patches... It was a (bad) joke. I don't really think my laptop would work all that well without PCI. Bjørn ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 16:57 ` Bjørn Mork @ 2012-07-31 0:22 ` Huang Ying 0 siblings, 0 replies; 89+ messages in thread From: Huang Ying @ 2012-07-31 0:22 UTC (permalink / raw) To: Bjørn Mork Cc: huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Alan Stern On Mon, 2012-07-30 at 18:57 +0200, Bjørn Mork wrote: > huang ying <huang.ying.caritas@gmail.com> writes: > > > On Mon, Jul 30, 2012 at 4:08 PM, Bjørn Mork <bjorn@mork.no> wrote: > >> Huang Ying <ying.huang@intel.com> writes: > >> > >>> Do you have time to test the following patch to fix the lspci issue? > >>> > >>> Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > >> > >> > >> Sure. But keep this going and I will file a request for modular build > >> of the PCI subsystem :-) > > > > Why? All not so old PC hardware has PCI/PCIe devices. > > So that I didn't have to reboot all the time to test your new patches... > > It was a (bad) joke. I don't really think my laptop would work all that > well without PCI. Haha, understood now. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 3:15 ` Huang Ying 2012-07-30 8:08 ` Bjørn Mork @ 2012-07-30 14:19 ` Alan Stern 2012-07-31 0:24 ` Huang Ying 2012-07-31 3:18 ` Huang Ying 1 sibling, 2 replies; 89+ messages in thread From: Alan Stern @ 2012-07-30 14:19 UTC (permalink / raw) To: Huang Ying Cc: Bjørn Mork, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Mon, 30 Jul 2012, Huang Ying wrote: > > Yup, that worked in the quick test I just did. > > > > lspci reading the device config will still not wake the bridge, but I > > assume that is intentional? But loading the device driver now wakes > > both the bridge and the device, so that works. > > Do you have time to test the following patch to fix the lspci issue? > > Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > > This patch fixes the following bug: > > http://marc.info/?l=linux-pci&m=134338059022620&w=2 > > Where lspci does not work properly if a device and the corresponding > parent bridge (such as PCIe port) is suspended. This is because the > device configuration space registers will be not accessible if the > corresponding parent bridge is suspended. > > To solve the issue, the bridge/PCIe port connected to the device is > put into active state before read/write configuration space registers. What happens when you run lspci and the device is in D3cold? Then even if the parent bridge is active, lspci will still fail. It seems that in this case you need to resume the device itself, not just its parent. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 14:19 ` Alan Stern @ 2012-07-31 0:24 ` Huang Ying 2012-07-31 3:18 ` Huang Ying 1 sibling, 0 replies; 89+ messages in thread From: Huang Ying @ 2012-07-31 0:24 UTC (permalink / raw) To: Alan Stern Cc: Bjørn Mork, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Mon, 2012-07-30 at 10:19 -0400, Alan Stern wrote: > On Mon, 30 Jul 2012, Huang Ying wrote: > > > > Yup, that worked in the quick test I just did. > > > > > > lspci reading the device config will still not wake the bridge, but I > > > assume that is intentional? But loading the device driver now wakes > > > both the bridge and the device, so that works. > > > > Do you have time to test the following patch to fix the lspci issue? > > > > Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > > > > This patch fixes the following bug: > > > > http://marc.info/?l=linux-pci&m=134338059022620&w=2 > > > > Where lspci does not work properly if a device and the corresponding > > parent bridge (such as PCIe port) is suspended. This is because the > > device configuration space registers will be not accessible if the > > corresponding parent bridge is suspended. > > > > To solve the issue, the bridge/PCIe port connected to the device is > > put into active state before read/write configuration space registers. > > What happens when you run lspci and the device is in D3cold? Then even > if the parent bridge is active, lspci will still fail. > > It seems that in this case you need to resume the device itself, not > just its parent. Yes. Will do that. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-30 14:19 ` Alan Stern 2012-07-31 0:24 ` Huang Ying @ 2012-07-31 3:18 ` Huang Ying 2012-07-31 17:07 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Huang Ying @ 2012-07-31 3:18 UTC (permalink / raw) To: Alan Stern Cc: Bjørn Mork, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Mon, 2012-07-30 at 10:19 -0400, Alan Stern wrote: > On Mon, 30 Jul 2012, Huang Ying wrote: > > > > Yup, that worked in the quick test I just did. > > > > > > lspci reading the device config will still not wake the bridge, but I > > > assume that is intentional? But loading the device driver now wakes > > > both the bridge and the device, so that works. > > > > Do you have time to test the following patch to fix the lspci issue? > > > > Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > > > > This patch fixes the following bug: > > > > http://marc.info/?l=linux-pci&m=134338059022620&w=2 > > > > Where lspci does not work properly if a device and the corresponding > > parent bridge (such as PCIe port) is suspended. This is because the > > device configuration space registers will be not accessible if the > > corresponding parent bridge is suspended. > > > > To solve the issue, the bridge/PCIe port connected to the device is > > put into active state before read/write configuration space registers. > > What happens when you run lspci and the device is in D3cold? Then even > if the parent bridge is active, lspci will still fail. > > It seems that in this case you need to resume the device itself, not > just its parent. How about the following patch? Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg This patch fixes the following bug: http://marc.info/?l=linux-pci&m=134338059022620&w=2 Where lspci does not work properly if a device and the corresponding parent bridge (such as PCIe port) is suspended. This is because the device configuration space registers will be not accessible if the corresponding parent bridge is suspended or the device is put into D3cold state. To solve the issue, the bridge/PCIe port connected to the device is put into active state before read/write configuration space registers. If the device is in D3cold state, it will be put into active state too. To avoid resume/suspend PCIe port for each configuration register read/write, a small delay is added before the PCIe port to go suspended. Reported-by: Bjorn Mork <bjorn@mork.no> Signed-off-by: Huang Ying <ying.huang@intel.com> --- drivers/pci/pci-sysfs.c | 68 ++++++++++++++++++++++++++++++----------- drivers/pci/pcie/portdrv_pci.c | 9 +++++ 2 files changed, 60 insertions(+), 17 deletions(-) --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -463,15 +463,17 @@ pci_read_config(struct file *filp, struc struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { - struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj)); + struct device *dev = container_of(kobj,struct device,kobj); + struct pci_dev *pdev = to_pci_dev(dev); + struct device *parent = dev->parent; unsigned int size = 64; loff_t init_off = off; u8 *data = (u8*) buf; /* Several chips lock up trying to read undefined config space */ if (security_capable(filp->f_cred, &init_user_ns, CAP_SYS_ADMIN) == 0) { - size = dev->cfg_size; - } else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) { + size = pdev->cfg_size; + } else if (pdev->hdr_type == PCI_HEADER_TYPE_CARDBUS) { size = 128; } @@ -484,9 +486,20 @@ pci_read_config(struct file *filp, struc size = count; } + if (parent) + pm_runtime_get_sync(parent); + pm_runtime_get_noresume(dev); + /* + * pdev->current_state is set to PCI_D3cold during suspending, + * so wait until suspending completes + */ + pm_runtime_barrier(dev); + if (pdev->current_state == PCI_D3cold) + pm_runtime_resume(dev); + if ((off & 1) && size) { u8 val; - pci_user_read_config_byte(dev, off, &val); + pci_user_read_config_byte(pdev, off, &val); data[off - init_off] = val; off++; size--; @@ -494,7 +507,7 @@ pci_read_config(struct file *filp, struc if ((off & 3) && size > 2) { u16 val; - pci_user_read_config_word(dev, off, &val); + pci_user_read_config_word(pdev, off, &val); data[off - init_off] = val & 0xff; data[off - init_off + 1] = (val >> 8) & 0xff; off += 2; @@ -503,7 +516,7 @@ pci_read_config(struct file *filp, struc while (size > 3) { u32 val; - pci_user_read_config_dword(dev, off, &val); + pci_user_read_config_dword(pdev, off, &val); data[off - init_off] = val & 0xff; data[off - init_off + 1] = (val >> 8) & 0xff; data[off - init_off + 2] = (val >> 16) & 0xff; @@ -514,7 +527,7 @@ pci_read_config(struct file *filp, struc if (size >= 2) { u16 val; - pci_user_read_config_word(dev, off, &val); + pci_user_read_config_word(pdev, off, &val); data[off - init_off] = val & 0xff; data[off - init_off + 1] = (val >> 8) & 0xff; off += 2; @@ -523,12 +536,16 @@ pci_read_config(struct file *filp, struc if (size > 0) { u8 val; - pci_user_read_config_byte(dev, off, &val); + pci_user_read_config_byte(pdev, off, &val); data[off - init_off] = val; off++; --size; } + pm_runtime_put(dev); + if (parent) + pm_runtime_put(parent); + return count; } @@ -537,20 +554,33 @@ pci_write_config(struct file* filp, stru struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { - struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj)); + struct device *dev = container_of(kobj,struct device,kobj); + struct pci_dev *pdev = to_pci_dev(dev); + struct device *parent = dev->parent; unsigned int size = count; loff_t init_off = off; u8 *data = (u8*) buf; - if (off > dev->cfg_size) + if (off > pdev->cfg_size) return 0; - if (off + count > dev->cfg_size) { - size = dev->cfg_size - off; + if (off + count > pdev->cfg_size) { + size = pdev->cfg_size - off; count = size; } + if (parent) + pm_runtime_get_sync(parent); + pm_runtime_get_noresume(dev); + /* + * pdev->current_state is set to PCI_D3cold during suspending, + * so wait until suspending completes + */ + pm_runtime_barrier(dev); + if (pdev->current_state == PCI_D3cold) + pm_runtime_resume(dev); + if ((off & 1) && size) { - pci_user_write_config_byte(dev, off, data[off - init_off]); + pci_user_write_config_byte(pdev, off, data[off - init_off]); off++; size--; } @@ -558,7 +588,7 @@ pci_write_config(struct file* filp, stru if ((off & 3) && size > 2) { u16 val = data[off - init_off]; val |= (u16) data[off - init_off + 1] << 8; - pci_user_write_config_word(dev, off, val); + pci_user_write_config_word(pdev, off, val); off += 2; size -= 2; } @@ -568,7 +598,7 @@ pci_write_config(struct file* filp, stru val |= (u32) data[off - init_off + 1] << 8; val |= (u32) data[off - init_off + 2] << 16; val |= (u32) data[off - init_off + 3] << 24; - pci_user_write_config_dword(dev, off, val); + pci_user_write_config_dword(pdev, off, val); off += 4; size -= 4; } @@ -576,17 +606,21 @@ pci_write_config(struct file* filp, stru if (size >= 2) { u16 val = data[off - init_off]; val |= (u16) data[off - init_off + 1] << 8; - pci_user_write_config_word(dev, off, val); + pci_user_write_config_word(pdev, off, val); off += 2; size -= 2; } if (size) { - pci_user_write_config_byte(dev, off, data[off - init_off]); + pci_user_write_config_byte(pdev, off, data[off - init_off]); off++; --size; } + pm_runtime_put(dev); + if (parent) + pm_runtime_put(parent); + return count; } --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -140,9 +140,17 @@ static int pcie_port_runtime_resume(stru { return 0; } + +static int pcie_port_runtime_idle(struct device *dev) +{ + /* Delay for a short while to prevent too frequent suspend/resume */ + pm_schedule_suspend(dev, 10); + return -EBUSY; +} #else #define pcie_port_runtime_suspend NULL #define pcie_port_runtime_resume NULL +#define pcie_port_runtime_idle NULL #endif static const struct dev_pm_ops pcie_portdrv_pm_ops = { @@ -155,6 +163,7 @@ static const struct dev_pm_ops pcie_port .resume_noirq = pcie_port_resume_noirq, .runtime_suspend = pcie_port_runtime_suspend, .runtime_resume = pcie_port_runtime_resume, + .runtime_idle = pcie_port_runtime_idle, }; #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops) ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-31 3:18 ` Huang Ying @ 2012-07-31 17:07 ` Alan Stern 0 siblings, 0 replies; 89+ messages in thread From: Alan Stern @ 2012-07-31 17:07 UTC (permalink / raw) To: Huang Ying Cc: Bjørn Mork, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Tue, 31 Jul 2012, Huang Ying wrote: > > What happens when you run lspci and the device is in D3cold? Then even > > if the parent bridge is active, lspci will still fail. > > > > It seems that in this case you need to resume the device itself, not > > just its parent. > > How about the following patch? > > Subject: [BUGFIX] PCI/PM: Keep parent bridge active when read/write config reg > > This patch fixes the following bug: > > http://marc.info/?l=linux-pci&m=134338059022620&w=2 > > Where lspci does not work properly if a device and the corresponding > parent bridge (such as PCIe port) is suspended. This is because the > device configuration space registers will be not accessible if the > corresponding parent bridge is suspended or the device is put into > D3cold state. > > To solve the issue, the bridge/PCIe port connected to the device is > put into active state before read/write configuration space registers. > If the device is in D3cold state, it will be put into active state > too. > > To avoid resume/suspend PCIe port for each configuration register > read/write, a small delay is added before the PCIe port to go > suspended. The patch looks reasonable to me, but I haven't tested it. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 5:35 ` Huang Ying 2012-07-27 9:11 ` Bjørn Mork @ 2012-07-27 15:03 ` Alan Stern 2012-07-27 19:11 ` Rafael J. Wysocki 1 sibling, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-27 15:03 UTC (permalink / raw) To: Huang Ying Cc: Bjørn Mork, huang ying, Rafael J. Wysocki, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Fri, 27 Jul 2012, Huang Ying wrote: > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > { > struct drv_dev_and_id *ddi = _ddi; > struct device *dev = &ddi->dev->dev; > + struct device *parent = dev->parent; > int rc; > > + /* The parent bridge must be in active state when probing */ > + if (parent) > + pm_runtime_get_sync(parent); Ooh, this is a very good point. I completely missed it. > /* Unbound PCI devices are always set to disabled and suspended. > * During probe, the device is set to enabled and active and the > * usage count is incremented. If the driver supports runtime PM, > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > pm_runtime_set_suspended(dev); > pm_runtime_put_noidle(dev); > } > + if (parent) > + pm_runtime_put(parent); You should use pm_runtime_put_sync(), not pm_runtime_put(). Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 15:03 ` Alan Stern @ 2012-07-27 19:11 ` Rafael J. Wysocki 2012-07-27 19:39 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-27 19:11 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Friday, July 27, 2012, Alan Stern wrote: > On Fri, 27 Jul 2012, Huang Ying wrote: > > > --- a/drivers/pci/pci-driver.c > > +++ b/drivers/pci/pci-driver.c > > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > > { > > struct drv_dev_and_id *ddi = _ddi; > > struct device *dev = &ddi->dev->dev; > > + struct device *parent = dev->parent; > > int rc; > > > > + /* The parent bridge must be in active state when probing */ > > + if (parent) > > + pm_runtime_get_sync(parent); > > Ooh, this is a very good point. I completely missed it. > > > /* Unbound PCI devices are always set to disabled and suspended. > > * During probe, the device is set to enabled and active and the > > * usage count is incremented. If the driver supports runtime PM, > > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > > pm_runtime_set_suspended(dev); > > pm_runtime_put_noidle(dev); > > } > > + if (parent) > > + pm_runtime_put(parent); > > You should use pm_runtime_put_sync(), not pm_runtime_put(). Hmm, why exactly? Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 19:11 ` Rafael J. Wysocki @ 2012-07-27 19:39 ` Alan Stern 2012-07-27 19:54 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-27 19:39 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > On Friday, July 27, 2012, Alan Stern wrote: > > On Fri, 27 Jul 2012, Huang Ying wrote: > > > > > --- a/drivers/pci/pci-driver.c > > > +++ b/drivers/pci/pci-driver.c > > > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > > > { > > > struct drv_dev_and_id *ddi = _ddi; > > > struct device *dev = &ddi->dev->dev; > > > + struct device *parent = dev->parent; > > > int rc; > > > > > > + /* The parent bridge must be in active state when probing */ > > > + if (parent) > > > + pm_runtime_get_sync(parent); > > > > Ooh, this is a very good point. I completely missed it. > > > > > /* Unbound PCI devices are always set to disabled and suspended. > > > * During probe, the device is set to enabled and active and the > > > * usage count is incremented. If the driver supports runtime PM, > > > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > > > pm_runtime_set_suspended(dev); > > > pm_runtime_put_noidle(dev); > > > } > > > + if (parent) > > > + pm_runtime_put(parent); > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > Hmm, why exactly? Because it's more efficient to do something directly than to run it in a workqueue. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 19:39 ` Alan Stern @ 2012-07-27 19:54 ` Rafael J. Wysocki 2012-07-28 16:12 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-27 19:54 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Friday, July 27, 2012, Alan Stern wrote: > On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > > > On Friday, July 27, 2012, Alan Stern wrote: > > > On Fri, 27 Jul 2012, Huang Ying wrote: > > > > > > > --- a/drivers/pci/pci-driver.c > > > > +++ b/drivers/pci/pci-driver.c > > > > @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) > > > > { > > > > struct drv_dev_and_id *ddi = _ddi; > > > > struct device *dev = &ddi->dev->dev; > > > > + struct device *parent = dev->parent; > > > > int rc; > > > > > > > > + /* The parent bridge must be in active state when probing */ > > > > + if (parent) > > > > + pm_runtime_get_sync(parent); > > > > > > Ooh, this is a very good point. I completely missed it. > > > > > > > /* Unbound PCI devices are always set to disabled and suspended. > > > > * During probe, the device is set to enabled and active and the > > > > * usage count is incremented. If the driver supports runtime PM, > > > > @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) > > > > pm_runtime_set_suspended(dev); > > > > pm_runtime_put_noidle(dev); > > > > } > > > > + if (parent) > > > > + pm_runtime_put(parent); > > > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > > > Hmm, why exactly? > > Because it's more efficient to do something directly than to run it in > a workqueue. Well, depends. If that results in a power off (the parent goes into D3 for example), we may wait as long as 10 ms for that to complete. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-27 19:54 ` Rafael J. Wysocki @ 2012-07-28 16:12 ` Alan Stern 2012-07-28 20:26 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-28 16:12 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > > > > > + if (parent) > > > > > + pm_runtime_put(parent); > > > > > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > > > > > Hmm, why exactly? > > > > Because it's more efficient to do something directly than to run it in > > a workqueue. > > Well, depends. If that results in a power off (the parent goes into > D3 for example), we may wait as long as 10 ms for that to complete. True, but so what? You'd also have to wait 10 ms for the workqueue item to complete if pm_runtime_put() was used, plus the additional overhead of scheduling the workqueue thread. Now, if the length of time required for the probe to run were an issue then yes, the synchronous routine could make things take longer. But probing is generally done asynchronously anyway, right? And usually what matters is the time before the device becomes available, not the time for the probe to run. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-28 16:12 ` Alan Stern @ 2012-07-28 20:26 ` Rafael J. Wysocki 2012-07-28 21:12 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-28 20:26 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Saturday, July 28, 2012, Alan Stern wrote: > On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > > > > > > > + if (parent) > > > > > > + pm_runtime_put(parent); > > > > > > > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > > > > > > > Hmm, why exactly? > > > > > > Because it's more efficient to do something directly than to run it in > > > a workqueue. > > > > Well, depends. If that results in a power off (the parent goes into > > D3 for example), we may wait as long as 10 ms for that to complete. > > True, but so what? You'd also have to wait 10 ms for the workqueue > item to complete if pm_runtime_put() was used, Are you sure? pm_runtime_put() leads to rpm_idle() with the RPM_ASYNC flag set, which causes it to queue up the work item and return immediately without waiting. Why exactly do you think I'd need to wait, then? > plus the additional overhead of scheduling the workqueue thread. > > Now, if the length of time required for the probe to run were an issue > then yes, the synchronous routine could make things take longer. But > probing is generally done asynchronously anyway, right? And usually > what matters is the time before the device becomes available, not the > time for the probe to run. Still, I see no reason to wait synchronously for the _parent_ to suspend. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-28 20:26 ` Rafael J. Wysocki @ 2012-07-28 21:12 ` Alan Stern 2012-07-29 13:55 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-28 21:12 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Sat, 28 Jul 2012, Rafael J. Wysocki wrote: > On Saturday, July 28, 2012, Alan Stern wrote: > > On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > > > > > > > > > + if (parent) > > > > > > > + pm_runtime_put(parent); > > > > > > > > > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > > > > > > > > > Hmm, why exactly? > > > > > > > > Because it's more efficient to do something directly than to run it in > > > > a workqueue. > > > > > > Well, depends. If that results in a power off (the parent goes into > > > D3 for example), we may wait as long as 10 ms for that to complete. > > > > True, but so what? You'd also have to wait 10 ms for the workqueue > > item to complete if pm_runtime_put() was used, > > Are you sure? pm_runtime_put() leads to rpm_idle() with the RPM_ASYNC > flag set, which causes it to queue up the work item and return immediately > without waiting. Why exactly do you think I'd need to wait, then? What I mean is, it takes 10 ms for the parent to suspend regardless of whether or not you use the _sync form of the call. If you're waiting for the parent to suspend, you would therefore have to wait 10 ms in either case. Likewise, if you're waiting for the PCI device to become usable then you don't have to wait for 10 ms, because you can use it as soon as the probe routine returns. > > plus the additional overhead of scheduling the workqueue thread. > > > > Now, if the length of time required for the probe to run were an issue > > then yes, the synchronous routine could make things take longer. But > > probing is generally done asynchronously anyway, right? And usually > > what matters is the time before the device becomes available, not the > > time for the probe to run. > > Still, I see no reason to wait synchronously for the _parent_ to suspend. Why not? There's no penalty, particularly since most device probing happens asynchronously these days anyway. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-28 21:12 ` Alan Stern @ 2012-07-29 13:55 ` Rafael J. Wysocki 2012-07-29 14:55 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-29 13:55 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Saturday, July 28, 2012, Alan Stern wrote: > On Sat, 28 Jul 2012, Rafael J. Wysocki wrote: > > > On Saturday, July 28, 2012, Alan Stern wrote: > > > On Fri, 27 Jul 2012, Rafael J. Wysocki wrote: > > > > > > > > > > > + if (parent) > > > > > > > > + pm_runtime_put(parent); > > > > > > > > > > > > > > You should use pm_runtime_put_sync(), not pm_runtime_put(). > > > > > > > > > > > > Hmm, why exactly? > > > > > > > > > > Because it's more efficient to do something directly than to run it in > > > > > a workqueue. > > > > > > > > Well, depends. If that results in a power off (the parent goes into > > > > D3 for example), we may wait as long as 10 ms for that to complete. > > > > > > True, but so what? You'd also have to wait 10 ms for the workqueue > > > item to complete if pm_runtime_put() was used, > > > > Are you sure? pm_runtime_put() leads to rpm_idle() with the RPM_ASYNC > > flag set, which causes it to queue up the work item and return immediately > > without waiting. Why exactly do you think I'd need to wait, then? > > What I mean is, it takes 10 ms for the parent to suspend regardless of > whether or not you use the _sync form of the call. If you're waiting > for the parent to suspend, you would therefore have to wait 10 ms in > either case. > > Likewise, if you're waiting for the PCI device to become usable then > you don't have to wait for 10 ms, because you can use it as soon as the > probe routine returns. The difference is, if you use _put_sync(), you need to wait the extra 10 ms for local_pci_probe() to return (if the parent is actually suspended), although you might not need to wait for it if you used _put(), right? Which, to me, means that using _put_sync() may not be always better. It probably doesn't matter a lot, but then the workqueue overhead shouldn't matter a lot either. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-29 13:55 ` Rafael J. Wysocki @ 2012-07-29 14:55 ` Alan Stern 2012-07-29 19:18 ` Rafael J. Wysocki 2012-07-29 20:12 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Jassi Brar 0 siblings, 2 replies; 89+ messages in thread From: Alan Stern @ 2012-07-29 14:55 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Sun, 29 Jul 2012, Rafael J. Wysocki wrote: > The difference is, if you use _put_sync(), you need to wait the extra 10 ms > for local_pci_probe() to return (if the parent is actually suspended), > although you might not need to wait for it if you used _put(), right? Yes, that's the difference. But who waits for local_pci_probe() to return? :-) > Which, to me, means that using _put_sync() may not be always better. > It probably doesn't matter a lot, but then the workqueue overhead shouldn't > matter a lot either. It's that in the end, the extra overhead is pretty small. For me there's also an issue of style: If you do a synchronous get then it looks odd not to do a synchronous put. My feeling has always been that the async routines are for use in non-process contexts, where the sync routines can't be used. Using them just to return a little more quickly is a foreign idea. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-29 14:55 ` Alan Stern @ 2012-07-29 19:18 ` Rafael J. Wysocki 2012-07-31 20:31 ` Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) Rafael J. Wysocki 2012-07-29 20:12 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Jassi Brar 1 sibling, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-29 19:18 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Sunday, July 29, 2012, Alan Stern wrote: > On Sun, 29 Jul 2012, Rafael J. Wysocki wrote: > > > The difference is, if you use _put_sync(), you need to wait the extra 10 ms > > for local_pci_probe() to return (if the parent is actually suspended), > > although you might not need to wait for it if you used _put(), right? > > Yes, that's the difference. But who waits for local_pci_probe() to > return? :-) pci_register_driver() might, but that's not a big deal. Hot-plug might as well, though. > > Which, to me, means that using _put_sync() may not be always better. > > It probably doesn't matter a lot, but then the workqueue overhead shouldn't > > matter a lot either. > > It's that in the end, the extra overhead is pretty small. For me > there's also an issue of style: If you do a synchronous get then it > looks odd not to do a synchronous put. My feeling has always been that > the async routines are for use in non-process contexts, where the sync > routines can't be used. Using them just to return a little more > quickly is a foreign idea. I see. :-) The reason for using sync get is quite obvious: we want to be able to access the device later on. For sync put that's not so clear, though. There are cases when we definitely want to do it, like the failing .probe() in which we want to disable runtime PM next to the put, but usually it doesn't hurt (too much) to defer it IMO. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-07-29 19:18 ` Rafael J. Wysocki @ 2012-07-31 20:31 ` Rafael J. Wysocki 2012-07-31 21:05 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-31 20:31 UTC (permalink / raw) To: Alan Stern Cc: Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb, Linux PM list On Sunday, July 29, 2012, Rafael J. Wysocki wrote: > On Sunday, July 29, 2012, Alan Stern wrote: > > On Sun, 29 Jul 2012, Rafael J. Wysocki wrote: > > > > > The difference is, if you use _put_sync(), you need to wait the extra 10 ms > > > for local_pci_probe() to return (if the parent is actually suspended), > > > although you might not need to wait for it if you used _put(), right? > > > > Yes, that's the difference. But who waits for local_pci_probe() to > > return? :-) > > pci_register_driver() might, but that's not a big deal. Hot-plug might > as well, though. > > > > Which, to me, means that using _put_sync() may not be always better. > > > It probably doesn't matter a lot, but then the workqueue overhead shouldn't > > > matter a lot either. > > > > It's that in the end, the extra overhead is pretty small. For me > > there's also an issue of style: If you do a synchronous get then it > > looks odd not to do a synchronous put. My feeling has always been that > > the async routines are for use in non-process contexts, where the sync > > routines can't be used. Using them just to return a little more > > quickly is a foreign idea. > > I see. :-) > > The reason for using sync get is quite obvious: we want to be able to access > the device later on. For sync put that's not so clear, though. There are cases > when we definitely want to do it, like the failing .probe() in which we want to > disable runtime PM next to the put, but usually it doesn't hurt (too much) to > defer it IMO. Now it occured to me that perhaps we don't need the current asynchronous pm_runtime_get() at all. The usefulness of it is quite questionable, because either we want to resume the device immediately, for which pm_runtime_get_sync() should be used, or we just want to bump up the usage counter, in which cases pm_runtime_get_noresume() should always be sufficient. I fail to see any particularly compelling use case for pm_runtime_get() doing an asynchronous resume at the moment, but perhaps that's just me. However, I receive reports of people using pm_runtime_get() where they really should use pm_runtime_get_sync(), so I wonder if we can simply rename pm_runtime_get_sync() as pm_runtime_get() and drop the asynchronous version altogether? Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-07-31 20:31 ` Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) Rafael J. Wysocki @ 2012-07-31 21:05 ` Alan Stern 2012-07-31 21:34 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-31 21:05 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list [CC: list trimmed] On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > Now it occured to me that perhaps we don't need the current asynchronous > pm_runtime_get() at all. The usefulness of it is quite questionable, because > either we want to resume the device immediately, for which pm_runtime_get_sync() > should be used, or we just want to bump up the usage counter, in which cases > pm_runtime_get_noresume() should always be sufficient. I fail to see any > particularly compelling use case for pm_runtime_get() doing an asynchronous > resume at the moment, but perhaps that's just me. There are indeed valid uses for pm_runtime_get(). We are forced to use it in non-sleepable contexts when we want to resume the device as quickly as possible. Example: a driver receives an I/O request from an interrupt handler. > However, I receive reports of people using pm_runtime_get() where they really > should use pm_runtime_get_sync(), so I wonder if we can simply rename > pm_runtime_get_sync() as pm_runtime_get() and drop the asynchronous version > altogether? Well, IMO the naming should have been the other way around from the start. That is, we should have made pm_runtime_get be the synchronous routine and pm_runtime_get_async be the asynchronous one. But it's too late to change now. And no, we can't get rid of the async version. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-07-31 21:05 ` Alan Stern @ 2012-07-31 21:34 ` Rafael J. Wysocki 2012-07-31 21:49 ` Rafael J. Wysocki 2012-08-01 14:36 ` Alan Stern 0 siblings, 2 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-31 21:34 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Tuesday, July 31, 2012, Alan Stern wrote: > [CC: list trimmed] > > On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > > > Now it occured to me that perhaps we don't need the current asynchronous > > pm_runtime_get() at all. The usefulness of it is quite questionable, because > > either we want to resume the device immediately, for which pm_runtime_get_sync() > > should be used, or we just want to bump up the usage counter, in which cases > > pm_runtime_get_noresume() should always be sufficient. I fail to see any > > particularly compelling use case for pm_runtime_get() doing an asynchronous > > resume at the moment, but perhaps that's just me. > > There are indeed valid uses for pm_runtime_get(). We are forced to use > it in non-sleepable contexts when we want to resume the device as > quickly as possible. Example: a driver receives an I/O request from an > interrupt handler. Is it actually suitable to be used in such contexts? It doesn't give any guarantee that the device will be active when it returns, so the caller can't really rely on it. The caller always has to check if the device has been resumed before accessing it anyway, so it may as well do a _get_noresume(), do the check and do pm_request_resume() if needed directly. Now, as far as interrupt handlers are concerned, there are two cases: either the device has to be active to generate an interrupt (like PCI), or the interrupt is generated by something else on behalf of it. We don't seem to handle the first case very well right now, because in that case the interrupt handler will always know that the device is active, so it should do a _get_noresume() and then change the device's status to "active" without calling any kind of "resume", but we don't provide a helper for that. In the second case calling pm_runtime_get() doesn't really help either. I think it's better to do _get_noresume(), check the status and if "suspended", set a flag for the resume callback to do something specific before returning successfully, then call pm_request_resume() and return. > > However, I receive reports of people using pm_runtime_get() where they really > > should use pm_runtime_get_sync(), so I wonder if we can simply rename > > pm_runtime_get_sync() as pm_runtime_get() and drop the asynchronous version > > altogether? > > Well, IMO the naming should have been the other way around from the > start. That is, we should have made pm_runtime_get be the synchronous > routine and pm_runtime_get_async be the asynchronous one. But it's too > late to change now. I'm not sure it is too late. If we first change all the instances of pm_runtime_get() to pm_runtime_get_async() and then all of the instances of pm_runtime_get_sync() to pm_runtime_get(), it should be technically possible. Of course, it would be confusing, but that's a different matter. :-) > And no, we can't get rid of the async version. I'm still not sure of that. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-07-31 21:34 ` Rafael J. Wysocki @ 2012-07-31 21:49 ` Rafael J. Wysocki 2012-08-01 14:36 ` Alan Stern 1 sibling, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-31 21:49 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Tuesday, July 31, 2012, Rafael J. Wysocki wrote: > On Tuesday, July 31, 2012, Alan Stern wrote: > > [CC: list trimmed] > > > > On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > > > > > Now it occured to me that perhaps we don't need the current asynchronous > > > pm_runtime_get() at all. The usefulness of it is quite questionable, because > > > either we want to resume the device immediately, for which pm_runtime_get_sync() > > > should be used, or we just want to bump up the usage counter, in which cases > > > pm_runtime_get_noresume() should always be sufficient. I fail to see any > > > particularly compelling use case for pm_runtime_get() doing an asynchronous > > > resume at the moment, but perhaps that's just me. > > > > There are indeed valid uses for pm_runtime_get(). We are forced to use > > it in non-sleepable contexts when we want to resume the device as > > quickly as possible. Example: a driver receives an I/O request from an > > interrupt handler. > > Is it actually suitable to be used in such contexts? It doesn't give any > guarantee that the device will be active when it returns, so the caller can't > really rely on it. The caller always has to check if the device has been > resumed before accessing it anyway, so it may as well do a _get_noresume(), > do the check and do pm_request_resume() if needed directly. > > Now, as far as interrupt handlers are concerned, there are two cases: either > the device has to be active to generate an interrupt (like PCI), or the > interrupt is generated by something else on behalf of it. We don't seem to > handle the first case very well right now, because in that case the interrupt > handler will always know that the device is active, so it should do a > _get_noresume() and then change the device's status to "active" without > calling any kind of "resume", but we don't provide a helper for that. Unless, of course, this is a shared interrupt, in which case the handler may be invoked, because _another_ device has generated an interrupt, so the "active" check will have to be done anyway. > In the second case calling pm_runtime_get() doesn't really help either. > I think it's better to do _get_noresume(), check the status and if > "suspended", set a flag for the resume callback to do something specific > before returning successfully, then call pm_request_resume() and return. I realize that this may be somewhat racy, so perhaps we need something like pm_request_resume_and_call(dev, func) that will execute the given function once the device has been resumed (or just happens to be "active" when the resume work item is run for it). > > > However, I receive reports of people using pm_runtime_get() where they really > > > should use pm_runtime_get_sync(), so I wonder if we can simply rename > > > pm_runtime_get_sync() as pm_runtime_get() and drop the asynchronous version > > > altogether? > > > > Well, IMO the naming should have been the other way around from the > > start. That is, we should have made pm_runtime_get be the synchronous > > routine and pm_runtime_get_async be the asynchronous one. But it's too > > late to change now. > > I'm not sure it is too late. If we first change all the instances of > pm_runtime_get() to pm_runtime_get_async() and then all of the instances of > pm_runtime_get_sync() to pm_runtime_get(), it should be technically possible. > Of course, it would be confusing, but that's a different matter. :-) > > > And no, we can't get rid of the async version. > > I'm still not sure of that. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-07-31 21:34 ` Rafael J. Wysocki 2012-07-31 21:49 ` Rafael J. Wysocki @ 2012-08-01 14:36 ` Alan Stern 2012-08-01 21:24 ` Rafael J. Wysocki 1 sibling, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-01 14:36 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > On Tuesday, July 31, 2012, Alan Stern wrote: > > [CC: list trimmed] > > > > On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > > > > > Now it occured to me that perhaps we don't need the current asynchronous > > > pm_runtime_get() at all. The usefulness of it is quite questionable, because > > > either we want to resume the device immediately, for which pm_runtime_get_sync() > > > should be used, or we just want to bump up the usage counter, in which cases > > > pm_runtime_get_noresume() should always be sufficient. I fail to see any > > > particularly compelling use case for pm_runtime_get() doing an asynchronous > > > resume at the moment, but perhaps that's just me. > > > > There are indeed valid uses for pm_runtime_get(). We are forced to use > > it in non-sleepable contexts when we want to resume the device as > > quickly as possible. Example: a driver receives an I/O request from an > > interrupt handler. > > Is it actually suitable to be used in such contexts? It doesn't give any > guarantee that the device will be active when it returns, so the caller can't > really rely on it. Of course not. When you're in interrupt context, you can't wait around to see if the device will actually resume. (Unless you're using irq-safe runtime PM, but we can ignore that case.) > The caller always has to check if the device has been > resumed before accessing it anyway, so it may as well do a _get_noresume(), > do the check and do pm_request_resume() if needed directly. This is exactly equivalent to doing pm_runtime_get() followed by a check, except that it's longer. Yes, I agree that pm_runtime_get(dev) is nothing more than a shorthand way of doing pm_runtime_get_noresume(dev) followed by pm_request_resume(dev). That doesn't mean it should be eliminated. Shorthands are convenient. As another example, pm_runtime_get_sync(dev) is nothing more than a shorthand for pm_runtime_get_noresume(dev) followed by pm_runtime_resume(dev). IMO, having these joint functions that do a get/put combined with a suspend/resume/idle is very useful. > Now, as far as interrupt handlers are concerned, there are two cases: either > the device has to be active to generate an interrupt (like PCI), or the > interrupt is generated by something else on behalf of it. We don't seem to > handle the first case very well right now, because in that case the interrupt > handler will always know that the device is active, so it should do a > _get_noresume() and then change the device's status to "active" without > calling any kind of "resume", but we don't provide a helper for that. I disagree. Even if the device has to be active to generate an IRQ, it's possible for the interrupt handler to be delayed until after the device is suspended (unless the suspend routine explicitly calls synchronize_irq(), which would be pretty foolish). Hence the handler can't make any assumptions about the device's state. > In the > second case calling pm_runtime_get() doesn't really help either. I think it's > better to do _get_noresume(), check the status and if "suspended", set a flag > for the resume callback to do something specific before returning successfully, > then call pm_request_resume() and return. This is exactly equivalent to: pm_runtime_get(), check the status, if "suspended" then set a flag, otherwise do the work. Except that again, it's longer. Check out the sample driver code in section 9 of Documentation/power/runtime_pm.txt, especially the foo_read_or_write() routine. > > Well, IMO the naming should have been the other way around from the > > start. That is, we should have made pm_runtime_get be the synchronous > > routine and pm_runtime_get_async be the asynchronous one. But it's too > > late to change now. > > I'm not sure it is too late. If we first change all the instances of > pm_runtime_get() to pm_runtime_get_async() and then all of the instances of > pm_runtime_get_sync() to pm_runtime_get(), it should be technically possible. > Of course, it would be confusing, but that's a different matter. :-) If you're willing to risk a certain amount of confusion, count me in. :-) While you're changing names around, consider also adding a "_runtime" somewhere to: pm_children_suspended, pm_schedule_suspend, pm_request_idle, pm_request_resume, pm_request_autosuspend. For example, we could have pm_runtime_idle_async instead of pm_request_idle. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-01 14:36 ` Alan Stern @ 2012-08-01 21:24 ` Rafael J. Wysocki 2012-08-02 20:16 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-01 21:24 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Wednesday, August 01, 2012, Alan Stern wrote: > On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > > > On Tuesday, July 31, 2012, Alan Stern wrote: > > > [CC: list trimmed] > > > > > > On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > > > > > > > Now it occured to me that perhaps we don't need the current asynchronous > > > > pm_runtime_get() at all. The usefulness of it is quite questionable, because > > > > either we want to resume the device immediately, for which pm_runtime_get_sync() > > > > should be used, or we just want to bump up the usage counter, in which cases > > > > pm_runtime_get_noresume() should always be sufficient. I fail to see any > > > > particularly compelling use case for pm_runtime_get() doing an asynchronous > > > > resume at the moment, but perhaps that's just me. > > > > > > There are indeed valid uses for pm_runtime_get(). We are forced to use > > > it in non-sleepable contexts when we want to resume the device as > > > quickly as possible. Example: a driver receives an I/O request from an > > > interrupt handler. > > > > Is it actually suitable to be used in such contexts? It doesn't give any > > guarantee that the device will be active when it returns, so the caller can't > > really rely on it. > > Of course not. When you're in interrupt context, you can't wait around > to see if the device will actually resume. (Unless you're using > irq-safe runtime PM, but we can ignore that case.) > > > The caller always has to check if the device has been > > resumed before accessing it anyway, so it may as well do a _get_noresume(), > > do the check and do pm_request_resume() if needed directly. > > This is exactly equivalent to doing pm_runtime_get() followed by a > check, except that it's longer. Except that I meant something different from what I wrote, sorry about that (must be too much heat). What I really thought about was to do _get_noresume(), then check if the device is active and if not, queue up a work item (or another delayed execution in process context) that will do pm_runtime_resume() and then access the hardware. Why do I think it's better than plain pm_runtime_get()? Because the code path calling pm_runtime_resume() will know that it is safe to access the hardware after it has returned (unless it returns an error code, but that's exceptional). In contrast, with pm_runtime_get() there is no way to predict when the device is going to be resumed, so if the device happens to be suspended when pm_runtime_get() returns, the driver kind of has to poll it until it becomes active, or use a wait queue woken up from the resume callback, or do all of the processing in the resume callback itself (like in the example you mentioned). I'm not sure if the expectation that all driver writers will be able to implement any of these options correctly is a realistic one. > Yes, I agree that pm_runtime_get(dev) is nothing more than a shorthand > way of doing pm_runtime_get_noresume(dev) followed by > pm_request_resume(dev). That doesn't mean it should be eliminated. > Shorthands are convenient. > > As another example, pm_runtime_get_sync(dev) is nothing more than a > shorthand for pm_runtime_get_noresume(dev) followed by > pm_runtime_resume(dev). IMO, having these joint functions that do a > get/put combined with a suspend/resume/idle is very useful. > > > Now, as far as interrupt handlers are concerned, there are two cases: either > > the device has to be active to generate an interrupt (like PCI), or the > > interrupt is generated by something else on behalf of it. We don't seem to > > handle the first case very well right now, because in that case the interrupt > > handler will always know that the device is active, so it should do a > > _get_noresume() and then change the device's status to "active" without > > calling any kind of "resume", but we don't provide a helper for that. > > I disagree. Even if the device has to be active to generate an IRQ, > it's possible for the interrupt handler to be delayed until after the > device is suspended (unless the suspend routine explicitly calls > synchronize_irq(), which would be pretty foolish). Hence the handler > can't make any assumptions about the device's state. > > > In the > > second case calling pm_runtime_get() doesn't really help either. I think it's > > better to do _get_noresume(), check the status and if "suspended", set a flag > > for the resume callback to do something specific before returning successfully, > > then call pm_request_resume() and return. > > This is exactly equivalent to: pm_runtime_get(), check the status, if > "suspended" then set a flag, otherwise do the work. Except that again, > it's longer. > > Check out the sample driver code in section 9 of > Documentation/power/runtime_pm.txt, especially the foo_read_or_write() > routine. Well, that shouldn't need the is_suspended flag at all, methinks, and the reason it does need it is because it uses pm_runtime_get(). Moreover, processing requests in the resume callback is not something I'd recommend to anyone, because that's going to happen when the status of the device is RPM_RESUMING, we're holding a reference on the parent (if there's one) etc. So, it looks like I don't really agree with the example. :-) > > > Well, IMO the naming should have been the other way around from the > > > start. That is, we should have made pm_runtime_get be the synchronous > > > routine and pm_runtime_get_async be the asynchronous one. But it's too > > > late to change now. > > > > I'm not sure it is too late. If we first change all the instances of > > pm_runtime_get() to pm_runtime_get_async() and then all of the instances of > > pm_runtime_get_sync() to pm_runtime_get(), it should be technically possible. > > Of course, it would be confusing, but that's a different matter. :-) > > If you're willing to risk a certain amount of confusion, count me in. :-) > > While you're changing names around, consider also adding a "_runtime" > somewhere to: > > pm_children_suspended, > pm_schedule_suspend, > pm_request_idle, > pm_request_resume, > pm_request_autosuspend. > > For example, we could have pm_runtime_idle_async instead of > pm_request_idle. Well, these are not as misleading as pm_runtime_get(), at least in principle. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-01 21:24 ` Rafael J. Wysocki @ 2012-08-02 20:16 ` Alan Stern 2012-08-02 21:26 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-02 20:16 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list On Wed, 1 Aug 2012, Rafael J. Wysocki wrote: > What I really thought about was to do _get_noresume(), then check if the > device is active and if not, queue up a work item (or another delayed > execution in process context) that will do pm_runtime_resume() and > then access the hardware. > > Why do I think it's better than plain pm_runtime_get()? Because the code > path calling pm_runtime_resume() will know that it is safe to access the > hardware after it has returned (unless it returns an error code, but > that's exceptional). > > In contrast, with pm_runtime_get() there is no way to predict when the > device is going to be resumed, so if the device happens to be suspended > when pm_runtime_get() returns, the driver kind of has to poll it until > it becomes active, or use a wait queue woken up from the resume callback, > or do all of the processing in the resume callback itself (like in the > example you mentioned). I'm not sure if the expectation that all driver > writers will be able to implement any of these options correctly is a realistic > one. I don't know about that -- the logic involved in doing the processing within the resume callback isn't terribly complicated. At least, not much more complicated than the logic involved in setting up a custom work routine as you suggest. Anyway with the existing code, driver writers are free to choose whichever approach they prefer. > > Check out the sample driver code in section 9 of > > Documentation/power/runtime_pm.txt, especially the foo_read_or_write() > > routine. > > Well, that shouldn't need the is_suspended flag at all, methinks, and the > reason it does need it is because it uses pm_runtime_get(). Not so. Consider your scheme. When starting an I/O request, you call pm_runtime_get_noresume() and then check to see if the device is active, say by calling pm_runtime_suspended(). Suppose at that moment the suspend callback has just finished and has released the private spinlock. The device's status is still RPM_SUSPENDING, so pm_runtime_suspended() returns 0 and you try to carry out the I/O. To fix this problem you have to synchronize the status checking with the suspend/resume operations. This means the status changes have to occur under the protection of the private lock, which means a private flag is needed. > Moreover, > processing requests in the resume callback is not something I'd recommend > to anyone, because that's going to happen when the status of the device > is RPM_RESUMING, we're holding a reference on the parent (if there's one) etc. I don't see any problem with that. The parent's child_count will be incremented while the requests are being processed regardless. And if you've been waiting for the device to resume in order to carry out some processing, within the resume callback is the logical place to do the work. It avoids the overhead of a second context switch. > So, it looks like I don't really agree with the example. :-) Feel free to add your scheme as a second example in the document. :-) But please don't remove the first example, unless you can find something actually wrong with it. > > While you're changing names around, consider also adding a "_runtime" > > somewhere to: > > > > pm_children_suspended, > > pm_schedule_suspend, > > pm_request_idle, > > pm_request_resume, > > pm_request_autosuspend. > > > > For example, we could have pm_runtime_idle_async instead of > > pm_request_idle. > > Well, these are not as misleading as pm_runtime_get(), at least in principle. No, but it would be good to be more consistent about our naming. Making sure all the function names contain "_runtime" would help. I suppose we could keep pm_runtime_get_sync as is, and just change pm_runtime_get to pm_runtime_get_async (and likewise for _put). That could reduce the confusion during the changeover. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-02 20:16 ` Alan Stern @ 2012-08-02 21:26 ` Rafael J. Wysocki 2012-08-03 2:20 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-02 21:26 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Thursday, August 02, 2012, Alan Stern wrote: > On Wed, 1 Aug 2012, Rafael J. Wysocki wrote: > > > What I really thought about was to do _get_noresume(), then check if the > > device is active and if not, queue up a work item (or another delayed > > execution in process context) that will do pm_runtime_resume() and > > then access the hardware. > > > > Why do I think it's better than plain pm_runtime_get()? Because the code > > path calling pm_runtime_resume() will know that it is safe to access the > > hardware after it has returned (unless it returns an error code, but > > that's exceptional). > > > > In contrast, with pm_runtime_get() there is no way to predict when the > > device is going to be resumed, so if the device happens to be suspended > > when pm_runtime_get() returns, the driver kind of has to poll it until > > it becomes active, or use a wait queue woken up from the resume callback, > > or do all of the processing in the resume callback itself (like in the > > example you mentioned). I'm not sure if the expectation that all driver > > writers will be able to implement any of these options correctly is a realistic > > one. > > I don't know about that -- the logic involved in doing the processing > within the resume callback isn't terribly complicated. At least, not > much more complicated than the logic involved in setting up a custom > work routine as you suggest. That's why I had the idea of pm_request_resume_and_call(dev, func) described in this message: http://marc.info/?l=linux-usb&m=134377126804170&w=4 although perheps it would be better to call it something like pm_runtime_async_resume_and_call(dev, func). > Anyway with the existing code, driver writers are free to choose > whichever approach they prefer. I wonder how many instances of pm_runtime_get() used in a wrong way there are in the kernel right now. I guess I'll sacrifice some time to check that. > > > Check out the sample driver code in section 9 of > > > Documentation/power/runtime_pm.txt, especially the foo_read_or_write() > > > routine. > > > > Well, that shouldn't need the is_suspended flag at all, methinks, and the > > reason it does need it is because it uses pm_runtime_get(). > > Not so. Consider your scheme. When starting an I/O request, you call > pm_runtime_get_noresume() and then check to see if the device is > active, say by calling pm_runtime_suspended(). Suppose at that moment > the suspend callback has just finished and has released the private > spinlock. The device's status is still RPM_SUSPENDING, so > pm_runtime_suspended() returns 0 and you try to carry out the I/O. > > To fix this problem you have to synchronize the status checking with > the suspend/resume operations. This means the status changes have to > occur under the protection of the private lock, which means a private > flag is needed. What about checking if the status is RPM_ACTIVE under dev->power.lock? That's what rpm_resume() does, more or less. > > Moreover, > > processing requests in the resume callback is not something I'd recommend > > to anyone, because that's going to happen when the status of the device > > is RPM_RESUMING, we're holding a reference on the parent (if there's one) etc. > > I don't see any problem with that. The parent's child_count will be > incremented while the requests are being processed regardless. And if > you've been waiting for the device to resume in order to carry out some > processing, within the resume callback is the logical place to do the > work. Unless your _driver_ callback is actually executed from within a PM domain callback, for example, and something else may be waiting for it to complete, so your data processing is adding latencies to some other threads. I'm not making that up, by the way, that really can happen. And what if you are a parent waited for by a child to resume so that _it_ can process its data? Would you still want to process your data in the resume callback in that case? > It avoids the overhead of a second context switch. That may be avoided without processing data from within the resume callback, although not with the current code. > > So, it looks like I don't really agree with the example. :-) > > Feel free to add your scheme as a second example in the document. :-) > But please don't remove the first example, unless you can find > something actually wrong with it. Well, it should work in general, so it is not functionally wrong. However, I wouldn't like to regard it as the best thing we can offer. :-) > > > While you're changing names around, consider also adding a "_runtime" > > > somewhere to: > > > > > > pm_children_suspended, > > > pm_schedule_suspend, > > > pm_request_idle, > > > pm_request_resume, > > > pm_request_autosuspend. > > > > > > For example, we could have pm_runtime_idle_async instead of > > > pm_request_idle. > > > > Well, these are not as misleading as pm_runtime_get(), at least in principle. > > No, but it would be good to be more consistent about our naming. > Making sure all the function names contain "_runtime" would help. > > I suppose we could keep pm_runtime_get_sync as is, and just change > pm_runtime_get to pm_runtime_get_async (and likewise for _put). That > could reduce the confusion during the changeover. Changing pm_runtime_get() to pm_runtime_get_async() would be an improvement, although pm_runtime_get_but_do_not_resume_immediately() might even be better. Or even pm_runtime_get_but_do_not_access_hardware_when_it_returns(). ;-) I see no reason to have any of those things, though. Yes, they _may_ be useful to someone knowing the runtime PM core internals to save a few lines of code in some places, but generally they lead people to make serious mistakes that tend to be difficult to debug. For this very reason pm_runtime_get() is a bad interface and I wish we hadn't introduced it at all. Even if we give it a more descriptive name, it won't be much better. And note how that doesn't apply to the pm_runtime_put*() family. After all, doing pm_runtime_put() instead of pm_runtime_put_sync() will never lead to accessing registers of a suspended device. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-02 21:26 ` Rafael J. Wysocki @ 2012-08-03 2:20 ` Alan Stern 2012-08-03 3:37 ` Ming Lei ` (2 more replies) 0 siblings, 3 replies; 89+ messages in thread From: Alan Stern @ 2012-08-03 2:20 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > I don't know about that -- the logic involved in doing the processing > > within the resume callback isn't terribly complicated. At least, not > > much more complicated than the logic involved in setting up a custom > > work routine as you suggest. > > That's why I had the idea of pm_request_resume_and_call(dev, func) > described in this message: > > http://marc.info/?l=linux-usb&m=134377126804170&w=4 > > although perheps it would be better to call it something like > pm_runtime_async_resume_and_call(dev, func). Hmmm. You'd probably want a version that does a "get" at the same time. I suppose you would call func directly if the device was already resumed, without going through the workqueue? Yes, I agree this would be a better interface then pm_runtime_get. > > > Well, that shouldn't need the is_suspended flag at all, methinks, and the > > > reason it does need it is because it uses pm_runtime_get(). > > > > Not so. Consider your scheme. When starting an I/O request, you call > > pm_runtime_get_noresume() and then check to see if the device is > > active, say by calling pm_runtime_suspended(). Suppose at that moment > > the suspend callback has just finished and has released the private > > spinlock. The device's status is still RPM_SUSPENDING, so > > pm_runtime_suspended() returns 0 and you try to carry out the I/O. > > > > To fix this problem you have to synchronize the status checking with > > the suspend/resume operations. This means the status changes have to > > occur under the protection of the private lock, which means a private > > flag is needed. > > What about checking if the status is RPM_ACTIVE under dev->power.lock? > That's what rpm_resume() does, more or less. That wouldn't solve the race described above. > > > Moreover, > > > processing requests in the resume callback is not something I'd recommend > > > to anyone, because that's going to happen when the status of the device > > > is RPM_RESUMING, we're holding a reference on the parent (if there's one) etc. > > > > I don't see any problem with that. The parent's child_count will be > > incremented while the requests are being processed regardless. And if > > you've been waiting for the device to resume in order to carry out some > > processing, within the resume callback is the logical place to do the > > work. > > Unless your _driver_ callback is actually executed from within a PM domain > callback, for example, and something else may be waiting for it to complete, > so your data processing is adding latencies to some other threads. I'm not > making that up, by the way, that really can happen. > > And what if you are a parent waited for by a child to resume so that _it_ > can process its data? Would you still want to process your data in the > resume callback in that case? Okay, those are valid reasons. (Although a device handling I/O requests isn't likely to have a child with its own independent I/O handling.) > > I suppose we could keep pm_runtime_get_sync as is, and just change > > pm_runtime_get to pm_runtime_get_async (and likewise for _put). That > > could reduce the confusion during the changeover. > > Changing pm_runtime_get() to pm_runtime_get_async() would be an improvement, > although pm_runtime_get_but_do_not_resume_immediately() might even be better. > Or even pm_runtime_get_but_do_not_access_hardware_when_it_returns(). ;-) > > I see no reason to have any of those things, though. Yes, they _may_ be > useful to someone knowing the runtime PM core internals to save a few lines > of code in some places, but generally they lead people to make serious mistakes > that tend to be difficult to debug. For this very reason pm_runtime_get() is a > bad interface and I wish we hadn't introduced it at all. Even if we give it > a more descriptive name, it won't be much better. > > And note how that doesn't apply to the pm_runtime_put*() family. After all, > doing pm_runtime_put() instead of pm_runtime_put_sync() will never lead to > accessing registers of a suspended device. All right. But I still think "pm_runtime_put_async" is better than "pm_runtime_put". At least it forces people to think about what they're doing. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 2:20 ` Alan Stern @ 2012-08-03 3:37 ` Ming Lei 2012-08-03 14:28 ` Alan Stern 2012-08-04 19:47 ` Rafael J. Wysocki 2012-08-03 14:05 ` Alan Stern 2012-08-04 19:35 ` Rafael J. Wysocki 2 siblings, 2 replies; 89+ messages in thread From: Ming Lei @ 2012-08-03 3:37 UTC (permalink / raw) To: Alan Stern; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Fri, Aug 3, 2012 at 10:20 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > Hmmm. You'd probably want a version that does a "get" at the same > time. I suppose you would call func directly if the device was already > resumed, without going through the workqueue? Maybe it isn't good, the 'func' might not be run in the current context (irq context or some spinlock is held). >> And what if you are a parent waited for by a child to resume so that _it_ >> can process its data? Would you still want to process your data in the >> resume callback in that case? Looks the child is always resumed after its parent completes the resuming, and current pm_runtime_get doesn't delay the resume of the parent, and just make the .runtime_resume run in another context. Also are there actual examples about the above situation? > > Okay, those are valid reasons. (Although a device handling I/O > requests isn't likely to have a child with its own independent I/O > handling.) IMO, the .runtime_resume callback can handle the IO things easily via scheduling worker function if the driver don't want to delay its children's resume. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 3:37 ` Ming Lei @ 2012-08-03 14:28 ` Alan Stern 2012-08-04 19:47 ` Rafael J. Wysocki 1 sibling, 0 replies; 89+ messages in thread From: Alan Stern @ 2012-08-03 14:28 UTC (permalink / raw) To: Ming Lei; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Fri, 3 Aug 2012, Ming Lei wrote: > On Fri, Aug 3, 2012 at 10:20 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > Hmmm. You'd probably want a version that does a "get" at the same > > time. I suppose you would call func directly if the device was already > > resumed, without going through the workqueue? > > Maybe it isn't good, the 'func' might not be run in the current context > (irq context or some spinlock is held). True. But we don't want to wait for the workqueue if the device is already at full power. Suggestions? > >> And what if you are a parent waited for by a child to resume so that _it_ > >> can process its data? Would you still want to process your data in the > >> resume callback in that case? > > Looks the child is always resumed after its parent completes the resuming, > and current pm_runtime_get doesn't delay the resume of the parent, and > just make the .runtime_resume run in another context. I don't understand. Rafael's point was that if the parent's resume callback did a bunch of real work, it would delay resuming the child because the child can't be resumed until the parent's resume callback returns. > Also are there actual examples about the above situation? I don't know of any. I suspect there aren't many examples. It wouldn't make much sense. > IMO, the .runtime_resume callback can handle the IO things easily > via scheduling worker function if the driver don't want to delay > its children's resume. That was one of Rafael's other suggestions. But calling pm_request_resume_and_call() is easier than scheduling a worker function. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 3:37 ` Ming Lei 2012-08-03 14:28 ` Alan Stern @ 2012-08-04 19:47 ` Rafael J. Wysocki 2012-08-04 20:25 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 19:47 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Friday, August 03, 2012, Ming Lei wrote: > On Fri, Aug 3, 2012 at 10:20 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > Hmmm. You'd probably want a version that does a "get" at the same > > time. I suppose you would call func directly if the device was already > > resumed, without going through the workqueue? > > Maybe it isn't good, the 'func' might not be run in the current context > (irq context or some spinlock is held). Then I'd say don't use this interface. If you have code that needs to be run in a different context, then you have to use a work item (or equivalent) anyway and you can do a synchronous runtime resume from there. The problem we want to address here is when there's code that should be run as soon as the device is active, preferably _without_ a context switch. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 19:47 ` Rafael J. Wysocki @ 2012-08-04 20:25 ` Alan Stern 2012-08-04 20:48 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-04 20:25 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > On Friday, August 03, 2012, Ming Lei wrote: > > On Fri, Aug 3, 2012 at 10:20 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > > > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > > > Hmmm. You'd probably want a version that does a "get" at the same > > > time. I suppose you would call func directly if the device was already > > > resumed, without going through the workqueue? > > > > Maybe it isn't good, the 'func' might not be run in the current context > > (irq context or some spinlock is held). > > Then I'd say don't use this interface. If you have code that needs to > be run in a different context, then you have to use a work item (or > equivalent) anyway and you can do a synchronous runtime resume from there. That wasn't what he meant. What if the code needs to run in the _same_ context as the caller? For example, with a spinlock held. func would need to know whether it should acquire the lock, which means it needs to know whether it was called directly or through the workqueue. I suppose we could pass it an extra argument with this information... but that's a little ugly. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 20:25 ` Alan Stern @ 2012-08-04 20:48 ` Rafael J. Wysocki 2012-08-04 20:48 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 20:48 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Saturday, August 04, 2012, Alan Stern wrote: > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > On Friday, August 03, 2012, Ming Lei wrote: > > > On Fri, Aug 3, 2012 at 10:20 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > > > > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > > > > > Hmmm. You'd probably want a version that does a "get" at the same > > > > time. I suppose you would call func directly if the device was already > > > > resumed, without going through the workqueue? > > > > > > Maybe it isn't good, the 'func' might not be run in the current context > > > (irq context or some spinlock is held). > > > > Then I'd say don't use this interface. If you have code that needs to > > be run in a different context, then you have to use a work item (or > > equivalent) anyway and you can do a synchronous runtime resume from there. > > That wasn't what he meant. What if the code needs to run in the _same_ > context as the caller? For example, with a spinlock held. I see. I think it wouldn't be unreasonable to require that func should take all of the necessary locks by itself. However, I believe that if func is going to be called through the workqueue, the usage counter should be incremented before the preceding resume and decremented after func returns by the workqueue thread. > func would need to know whether it should acquire the lock, which means it > needs to know whether it was called directly or through the workqueue. > > I suppose we could pass it an extra argument with this information... > but that's a little ugly. I agree. I'd prefer to avoid that, if possible. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 20:48 ` Rafael J. Wysocki @ 2012-08-04 20:48 ` Alan Stern 2012-08-04 21:15 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-04 20:48 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > That wasn't what he meant. What if the code needs to run in the _same_ > > context as the caller? For example, with a spinlock held. > > I see. I think it wouldn't be unreasonable to require that func should take > all of the necessary locks by itself. But then if func was called directly, because the device was at full power, it would deadlock trying to acquire a lock the caller already holds. > However, I believe that if func is going to be called through the workqueue, > the usage counter should be incremented before the preceding resume and > decremented after func returns by the workqueue thread. Okay. > > func would need to know whether it should acquire the lock, which means it > > needs to know whether it was called directly or through the workqueue. > > > > I suppose we could pass it an extra argument with this information... > > but that's a little ugly. > > I agree. I'd prefer to avoid that, if possible. Do you have any better suggestions? Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 20:48 ` Alan Stern @ 2012-08-04 21:15 ` Rafael J. Wysocki 2012-08-04 22:13 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 21:15 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Saturday, August 04, 2012, Alan Stern wrote: > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > > That wasn't what he meant. What if the code needs to run in the _same_ > > > context as the caller? For example, with a spinlock held. > > > > I see. I think it wouldn't be unreasonable to require that func should take > > all of the necessary locks by itself. > > But then if func was called directly, because the device was at full > power, it would deadlock trying to acquire a lock the caller already > holds. I wonder why the caller may want to take any locks beforehand? > > However, I believe that if func is going to be called through the workqueue, > > the usage counter should be incremented before the preceding resume and > > decremented after func returns by the workqueue thread. > > Okay. > > > > func would need to know whether it should acquire the lock, which means it > > > needs to know whether it was called directly or through the workqueue. > > > > > > I suppose we could pass it an extra argument with this information... > > > but that's a little ugly. > > > > I agree. I'd prefer to avoid that, if possible. > > Do you have any better suggestions? Hmm. What about pm_runtime_get_and_call(dev, func_sync, func_async), where func_sync() is to be called if the device is already active and func_async() is to be called if it has to be resumed from the workqueue? Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 21:15 ` Rafael J. Wysocki @ 2012-08-04 22:13 ` Alan Stern 2012-08-05 15:26 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-04 22:13 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > On Saturday, August 04, 2012, Alan Stern wrote: > > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > > > > That wasn't what he meant. What if the code needs to run in the _same_ > > > > context as the caller? For example, with a spinlock held. > > > > > > I see. I think it wouldn't be unreasonable to require that func should take > > > all of the necessary locks by itself. > > > > But then if func was called directly, because the device was at full > > power, it would deadlock trying to acquire a lock the caller already > > holds. > > I wonder why the caller may want to take any locks beforehand? Who knows? :-) The best answer may be for the caller not to hold any locks. In the runtime-PM document's example driver, the lock would be dropped before the resume-and-call. > > Do you have any better suggestions? > > Hmm. What about pm_runtime_get_and_call(dev, func_sync, func_async), where > func_sync() is to be called if the device is already active and func_async() > is to be called if it has to be resumed from the workqueue? That's a little better but not much. It would require storing two function pointers in the dev->power structure. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 22:13 ` Alan Stern @ 2012-08-05 15:26 ` Rafael J. Wysocki 2012-08-06 13:30 ` Ming Lei 2012-08-06 15:48 ` Alan Stern 0 siblings, 2 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-05 15:26 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Sunday, August 05, 2012, Alan Stern wrote: > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > On Saturday, August 04, 2012, Alan Stern wrote: > > > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > > > > > > That wasn't what he meant. What if the code needs to run in the _same_ > > > > > context as the caller? For example, with a spinlock held. > > > > > > > > I see. I think it wouldn't be unreasonable to require that func should take > > > > all of the necessary locks by itself. > > > > > > But then if func was called directly, because the device was at full > > > power, it would deadlock trying to acquire a lock the caller already > > > holds. > > > > I wonder why the caller may want to take any locks beforehand? > > Who knows? :-) > > The best answer may be for the caller not to hold any locks. In the > runtime-PM document's example driver, the lock would be dropped before > the resume-and-call. > > > > Do you have any better suggestions? > > > > Hmm. What about pm_runtime_get_and_call(dev, func_sync, func_async), where > > func_sync() is to be called if the device is already active and func_async() > > is to be called if it has to be resumed from the workqueue? > > That's a little better but not much. It would require storing two > function pointers in the dev->power structure. I don't really think we'll need to store func_sync in dev->power. At least I don't see a reason to do that at the moment. I also think that func_sync() would have to be called if runtime PM is disabled for the given device, so that callers don't have to check that condition themselves. What about the appended experimental patch? Rafael --- drivers/base/power/runtime.c | 82 +++++++++++++++++++++++++++++++++++++++---- include/linux/pm.h | 1 include/linux/pm_runtime.h | 14 +++++++ 3 files changed, 90 insertions(+), 7 deletions(-) Index: linux/drivers/base/power/runtime.c =================================================================== --- linux.orig/drivers/base/power/runtime.c +++ linux/drivers/base/power/runtime.c @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de goto out; } +void rpm_queue_up_resume(struct device *dev) +{ + dev->power.request = RPM_REQ_RESUME; + if (!dev->power.request_pending) { + dev->power.request_pending = true; + queue_work(pm_wq, &dev->power.work); + } +} + /** * rpm_resume - Carry out runtime resume of given device. * @dev: Device to resume. @@ -524,7 +533,9 @@ static int rpm_resume(struct device *dev * rather than cancelling it now only to restart it again in the near * future. */ - dev->power.request = RPM_REQ_NONE; + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) + dev->power.request = RPM_REQ_NONE; + if (!dev->power.timer_autosuspends) pm_runtime_deactivate_timer(dev); @@ -533,6 +544,12 @@ static int rpm_resume(struct device *dev goto out; } + if (dev->power.func && (rpmflags & RPM_ASYNC)) { + rpm_queue_up_resume(dev); + retval = 0; + goto out; + } + if (dev->power.runtime_status == RPM_RESUMING || dev->power.runtime_status == RPM_SUSPENDING) { DEFINE_WAIT(wait); @@ -591,11 +608,7 @@ static int rpm_resume(struct device *dev /* Carry out an asynchronous or a synchronous resume. */ if (rpmflags & RPM_ASYNC) { - dev->power.request = RPM_REQ_RESUME; - if (!dev->power.request_pending) { - dev->power.request_pending = true; - queue_work(pm_wq, &dev->power.work); - } + rpm_queue_up_resume(dev); retval = 0; goto out; } @@ -691,6 +704,7 @@ static int rpm_resume(struct device *dev static void pm_runtime_work(struct work_struct *work) { struct device *dev = container_of(work, struct device, power.work); + void (*func)(struct device *) = NULL; enum rpm_request req; spin_lock_irq(&dev->power.lock); @@ -715,12 +729,24 @@ static void pm_runtime_work(struct work_ rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); break; case RPM_REQ_RESUME: - rpm_resume(dev, RPM_NOWAIT); + func = dev->power.func; + if (func) { + dev->power.func = NULL; + pm_runtime_get_noresume(dev); + rpm_resume(dev, 0); + } else { + rpm_resume(dev, RPM_NOWAIT); + } break; } out: spin_unlock_irq(&dev->power.lock); + + if (func) { + func(dev); + pm_runtime_put(dev); + } } /** @@ -877,6 +903,48 @@ int __pm_runtime_resume(struct device *d } EXPORT_SYMBOL_GPL(__pm_runtime_resume); +int pm_runtime_get_and_call(struct device *dev, void (*func)(struct device *), + void (*func_async)(struct device *)) +{ + unsigned long flags; + int ret; + + atomic_inc(&dev->power.usage_count); + + spin_lock_irqsave(&dev->power.lock, flags); + + ret = dev->power.runtime_error; + if (ret) { + func = NULL; + goto out; + } + + if (dev->power.runtime_status != RPM_ACTIVE + && dev->power.disable_depth == 0) + func = NULL; + + if (!func && func_async) { + if (dev->power.func) { + ret = -EAGAIN; + goto out; + } else { + dev->power.func = func_async; + } + } + + rpm_resume(dev, RPM_ASYNC); + + out: + spin_unlock_irqrestore(&dev->power.lock, flags); + + if (func) { + func(dev); + return 1; + } + + return ret; +} + /** * __pm_runtime_set_status - Set runtime PM status of a device. * @dev: Device to handle. Index: linux/include/linux/pm.h =================================================================== --- linux.orig/include/linux/pm.h +++ linux/include/linux/pm.h @@ -547,6 +547,7 @@ struct dev_pm_info { unsigned long suspended_jiffies; unsigned long accounting_timestamp; struct dev_pm_qos_request *pq_req; + void (*func)(struct device *); #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ struct pm_qos_constraints *constraints; Index: linux/include/linux/pm_runtime.h =================================================================== --- linux.orig/include/linux/pm_runtime.h +++ linux/include/linux/pm_runtime.h @@ -47,6 +47,9 @@ extern void pm_runtime_set_autosuspend_d extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev); extern void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns); +extern int pm_runtime_get_and_call(struct device *dev, + void (*func)(struct device *), + void (*func_async)(struct device *)); static inline bool pm_children_suspended(struct device *dev) { @@ -150,6 +153,17 @@ static inline void pm_runtime_set_autosu static inline unsigned long pm_runtime_autosuspend_expiration( struct device *dev) { return 0; } +static inline int pm_runtime_get_and_call(struct device *dev, + void (*func)(struct device *), + void (*func_async)(struct device *)) +{ + if (func) { + func(dev); + return 1; + } + return 0; +} + #endif /* !CONFIG_PM_RUNTIME */ static inline int pm_runtime_idle(struct device *dev) ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-05 15:26 ` Rafael J. Wysocki @ 2012-08-06 13:30 ` Ming Lei 2012-08-06 14:47 ` Alan Stern 2012-08-06 15:48 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-06 13:30 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Sun, Aug 5, 2012 at 11:26 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > --- > drivers/base/power/runtime.c | 82 +++++++++++++++++++++++++++++++++++++++---- > include/linux/pm.h | 1 > include/linux/pm_runtime.h | 14 +++++++ > 3 files changed, 90 insertions(+), 7 deletions(-) > > Index: linux/drivers/base/power/runtime.c > =================================================================== > --- linux.orig/drivers/base/power/runtime.c > +++ linux/drivers/base/power/runtime.c > @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de > goto out; > } > > +void rpm_queue_up_resume(struct device *dev) > +{ > + dev->power.request = RPM_REQ_RESUME; > + if (!dev->power.request_pending) { > + dev->power.request_pending = true; > + queue_work(pm_wq, &dev->power.work); > + } > +} > + > /** > * rpm_resume - Carry out runtime resume of given device. > * @dev: Device to resume. > @@ -524,7 +533,9 @@ static int rpm_resume(struct device *dev > * rather than cancelling it now only to restart it again in the near > * future. > */ > - dev->power.request = RPM_REQ_NONE; > + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) > + dev->power.request = RPM_REQ_NONE; > + > if (!dev->power.timer_autosuspends) > pm_runtime_deactivate_timer(dev); > > @@ -533,6 +544,12 @@ static int rpm_resume(struct device *dev > goto out; > } > > + if (dev->power.func && (rpmflags & RPM_ASYNC)) { > + rpm_queue_up_resume(dev); > + retval = 0; > + goto out; > + } > + > if (dev->power.runtime_status == RPM_RESUMING > || dev->power.runtime_status == RPM_SUSPENDING) { > DEFINE_WAIT(wait); > @@ -591,11 +608,7 @@ static int rpm_resume(struct device *dev > > /* Carry out an asynchronous or a synchronous resume. */ > if (rpmflags & RPM_ASYNC) { > - dev->power.request = RPM_REQ_RESUME; > - if (!dev->power.request_pending) { > - dev->power.request_pending = true; > - queue_work(pm_wq, &dev->power.work); > - } > + rpm_queue_up_resume(dev); > retval = 0; > goto out; > } > @@ -691,6 +704,7 @@ static int rpm_resume(struct device *dev > static void pm_runtime_work(struct work_struct *work) > { > struct device *dev = container_of(work, struct device, power.work); > + void (*func)(struct device *) = NULL; > enum rpm_request req; > > spin_lock_irq(&dev->power.lock); > @@ -715,12 +729,24 @@ static void pm_runtime_work(struct work_ > rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); > break; > case RPM_REQ_RESUME: > - rpm_resume(dev, RPM_NOWAIT); > + func = dev->power.func; > + if (func) { > + dev->power.func = NULL; > + pm_runtime_get_noresume(dev); > + rpm_resume(dev, 0); > + } else { > + rpm_resume(dev, RPM_NOWAIT); > + } > break; > } > > out: > spin_unlock_irq(&dev->power.lock); > + > + if (func) { > + func(dev); > + pm_runtime_put(dev); > + } > } > > /** > @@ -877,6 +903,48 @@ int __pm_runtime_resume(struct device *d > } > EXPORT_SYMBOL_GPL(__pm_runtime_resume); > > +int pm_runtime_get_and_call(struct device *dev, void (*func)(struct device *), > + void (*func_async)(struct device *)) > +{ > + unsigned long flags; > + int ret; > + > + atomic_inc(&dev->power.usage_count); > + > + spin_lock_irqsave(&dev->power.lock, flags); > + > + ret = dev->power.runtime_error; > + if (ret) { > + func = NULL; > + goto out; > + } > + > + if (dev->power.runtime_status != RPM_ACTIVE > + && dev->power.disable_depth == 0) > + func = NULL; Looks the above is a bit odd, and your motivation is to call 'func' for a suspended and runtime-PM enabled device in irq context, isn't it? > + > + if (!func && func_async) { > + if (dev->power.func) { > + ret = -EAGAIN; > + goto out; > + } else { > + dev->power.func = func_async; > + } > + } > + > + rpm_resume(dev, RPM_ASYNC); > + > + out: > + spin_unlock_irqrestore(&dev->power.lock, flags); > + > + if (func) { > + func(dev); Maybe the return value should be passed to caller. Also the race between 'func' and its .runtime_resume callback should be stated in comment. In fact, maybe it is better to call 'func' always first, then call ' rpm_resume(dev, RPM_ASYNC);', otherwise the driver may be confused about the order between 'func' and its .runtime_resume callback. > + return 1; > + } > + > + return ret; > +} > + > /** > * __pm_runtime_set_status - Set runtime PM status of a device. > * @dev: Device to handle. > Index: linux/include/linux/pm.h > =================================================================== > --- linux.orig/include/linux/pm.h > +++ linux/include/linux/pm.h > @@ -547,6 +547,7 @@ struct dev_pm_info { > unsigned long suspended_jiffies; > unsigned long accounting_timestamp; > struct dev_pm_qos_request *pq_req; > + void (*func)(struct device *); Another way is to define 'func' as 'runtime_pre_resume' in 'struct dev_pm_ops', and there are some advantages about this way: - save one pointer in 'struct devices, since most of devices don't need the 'func' - well documents on 'runtime_pre_resume' - caller of pm_runtime_get_and_call may be happier, maybe just pm_runtime_get or *_aync is enough. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-06 13:30 ` Ming Lei @ 2012-08-06 14:47 ` Alan Stern 2012-08-07 1:35 ` Ming Lei 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-06 14:47 UTC (permalink / raw) To: Ming Lei; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Mon, 6 Aug 2012, Ming Lei wrote: > Maybe the return value should be passed to caller. Also the race between > 'func' and its .runtime_resume callback should be stated in comment. > > In fact, maybe it is better to call 'func' always first, then call > ' rpm_resume(dev, RPM_ASYNC);', otherwise the driver may > be confused about the order between 'func' and its .runtime_resume > callback. > Another way is to define 'func' as 'runtime_pre_resume' > in 'struct dev_pm_ops', and there are some advantages about this way: > > - save one pointer in 'struct devices, since most of devices > don't need the 'func' > - well documents on 'runtime_pre_resume' > - caller of pm_runtime_get_and_call may be happier, maybe just > pm_runtime_get or *_aync is enough. No, no, you have completely misunderstood the whole point of this change. The idea is for "func" to be called at a time when it is known that the device is at full power. That means it _has_ to be called after the runtime_resume callback returns. Also, "func" should not be stored in dev_pm_ops because it won't be a read-only value. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-06 14:47 ` Alan Stern @ 2012-08-07 1:35 ` Ming Lei 2012-08-07 11:23 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-07 1:35 UTC (permalink / raw) To: Alan Stern; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Mon, Aug 6, 2012 at 10:47 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > No, no, you have completely misunderstood the whole point of this > change. Sorry, you are right. And the callback should be renamed as '.runtime_post_resume', which should do something I/O related in theory just after device becomes active. > > The idea is for "func" to be called at a time when it is known that the > device is at full power. That means it _has_ to be called after the > runtime_resume callback returns. Yes, I agree, but I don't think it may make .runtime_post_resume not doable, do I? > > Also, "func" should not be stored in dev_pm_ops because it won't be a > read-only value. Sorry, could you explain it in detail that why the 'func' has to switch to multiple functions dynamically? I understand one function is enough and sometimes it can be bypassed with one flag(such as, ignore_post_resume is introduced in dev_pm_info) set. Also, the driver can store the device specific states in its own device instance to deal with different situations in the callback. If the idea is doable, we can save one pointer in 'struct device', since the 'func' may not be used by more than 90% devices, also have document benefit, even may simplify implementation of the mechanism. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 1:35 ` Ming Lei @ 2012-08-07 11:23 ` Rafael J. Wysocki 2012-08-07 15:14 ` Ming Lei 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-07 11:23 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Tuesday, August 07, 2012, Ming Lei wrote: > On Mon, Aug 6, 2012 at 10:47 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > No, no, you have completely misunderstood the whole point of this > > change. > > Sorry, you are right. And the callback should be renamed as > '.runtime_post_resume', which should do something I/O related in > theory just after device becomes active. > > > > > The idea is for "func" to be called at a time when it is known that the > > device is at full power. That means it _has_ to be called after the > > runtime_resume callback returns. > > Yes, I agree, but I don't think it may make .runtime_post_resume > not doable, do I? No more device PM callbacks, please. Besides, callbacks in struct dev_pm_ops are not only for drivers. > > Also, "func" should not be stored in dev_pm_ops because it won't be a > > read-only value. > > Sorry, could you explain it in detail that why the 'func' > has to switch to multiple functions dynamically? I understand > one function is enough and sometimes it can be bypassed with > one flag(such as, ignore_post_resume is introduced in dev_pm_info) > set. Also, the driver can store the device specific states > in its own device instance to deal with different situations in the callback. > > If the idea is doable, we can save one pointer in 'struct device', > since the 'func' may not be used by more than 90% devices, also > have document benefit, even may simplify implementation of the > mechanism. And how many struct device objects there are for the one extra pointer to matter, let alone the fact that you want to replace it by one extra pointer somewhere else? Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 11:23 ` Rafael J. Wysocki @ 2012-08-07 15:14 ` Ming Lei 2012-08-07 15:42 ` Alan Stern 2012-08-07 20:45 ` Rafael J. Wysocki 0 siblings, 2 replies; 89+ messages in thread From: Ming Lei @ 2012-08-07 15:14 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: >> Yes, I agree, but I don't think it may make .runtime_post_resume >> not doable, do I? > > No more device PM callbacks, please. IMO, what the patch is doing is to introduce one callback which is just called after .runtime_resume is completed, and you want to move something out of previous .runtime_resume and do it in another new callback to speedup resume, so it should be reasonable to introduce the .runtime_post_resume callback in logic. Also, the 'func' should be per driver, not per device since only one 'func' is enough for all same kind of devices driven by one same driver. > Besides, callbacks in struct dev_pm_ops are not only for drivers. All the current 3 runtime callbacks are for devices. If you mean they can be defined in bus/power_domain/device_type, .runtime_post_resume still can be defined there too. > >> > Also, "func" should not be stored in dev_pm_ops because it won't be a >> > read-only value. >> >> Sorry, could you explain it in detail that why the 'func' >> has to switch to multiple functions dynamically? I understand >> one function is enough and sometimes it can be bypassed with >> one flag(such as, ignore_post_resume is introduced in dev_pm_info) >> set. Also, the driver can store the device specific states >> in its own device instance to deal with different situations in the callback. >> >> If the idea is doable, we can save one pointer in 'struct device', >> since the 'func' may not be used by more than 90% devices, also >> have document benefit, even may simplify implementation of the >> mechanism. > > And how many struct device objects there are for the one extra pointer to > matter, let alone the fact that you want to replace it by one extra pointer > somewhere else? For example, in the pandaboard(one omap4 based small system), follows the count of device instances: [root@root]#dmesg | grep device_add | wc -l 471 The above is just a simple configuration(no graphics, no video/video, only console enabled) on Pandaboard. If the callback may be defined in dev_pm_info, not only memory can be saved, also there are other advantages described before. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 15:14 ` Ming Lei @ 2012-08-07 15:42 ` Alan Stern 2012-08-07 16:30 ` Ming Lei 2012-08-07 20:45 ` Rafael J. Wysocki 1 sibling, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-07 15:42 UTC (permalink / raw) To: Ming Lei; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Tue, 7 Aug 2012, Ming Lei wrote: > On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > >> Yes, I agree, but I don't think it may make .runtime_post_resume > >> not doable, do I? > > > > No more device PM callbacks, please. > > IMO, what the patch is doing is to introduce one callback which > is just called after .runtime_resume is completed, and you want > to move something out of previous .runtime_resume and do it > in another new callback to speedup resume, so it should be > reasonable to introduce the .runtime_post_resume callback in logic. No, that's really not what the patch is doing. The idea behind the new API is that "func" will be called as soon as we know the device is at full power. That could be after the next runtime resume or it could be right away. This is a one-time call; it should not be made _every_ time the device resumes. > Also, the 'func' should be per driver, not per device since only one > 'func' is enough for all same kind of devices driven by one same > driver. But what if the subsystem defines its own dev_pm_info structure? Then the driver's dev_pm_info will be ignored by the runtime PM core. All the subsystems would have to be changed. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 15:42 ` Alan Stern @ 2012-08-07 16:30 ` Ming Lei 2012-08-07 20:57 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-07 16:30 UTC (permalink / raw) To: Alan Stern; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Tue, Aug 7, 2012 at 11:42 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > No, that's really not what the patch is doing. > > The idea behind the new API is that "func" will be called as soon as we > know the device is at full power. That could be after the next runtime > resume or it could be right away. This is a one-time call; it should IMO, in the both two cases, the 'func' should be very similar with .runtime_post_resume from view of the caller because the caller don't know what the power state of the device is now, so they may always think the 'func' should do something similar done in .runtime_post_resume. Also .runtime_post_resume always knows the device's power state is active, which is same with 'func'. In fact, it doesn't matter if the active state is the 1st time or other times, does it? > not be made _every_ time the device resumes. Suppose the device is always resumed in the path(such as irq context), the callback is still called every time. If the .runtime_post_resume is to be a one-time call, that is easy to do it. Also I am wondering why the callback shouldn't be called after resume in sync context, and it may simplify implementation if the two contexts (sync vs. async) are kept consistent. > >> Also, the 'func' should be per driver, not per device since only one >> 'func' is enough for all same kind of devices driven by one same >> driver. > > But what if the subsystem defines its own dev_pm_info structure? Then > the driver's dev_pm_info will be ignored by the runtime PM core. All > the subsystems would have to be changed. Suppose .runtime_post_resume is introduced, the priority of dev_pm_info for .runtime_post_resume callback can be changed to adapt to the situation. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 16:30 ` Ming Lei @ 2012-08-07 20:57 ` Rafael J. Wysocki 0 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-07 20:57 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Tuesday, August 07, 2012, Ming Lei wrote: > On Tue, Aug 7, 2012 at 11:42 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > > > No, that's really not what the patch is doing. > > > > The idea behind the new API is that "func" will be called as soon as we > > know the device is at full power. That could be after the next runtime > > resume or it could be right away. This is a one-time call; it should > > IMO, in the both two cases, the 'func' should be very similar with > .runtime_post_resume from view of the caller because the caller > don't know what the power state of the device is now, so they may > always think the 'func' should do something similar done in > .runtime_post_resume. > > Also .runtime_post_resume always knows the device's power state > is active, which is same with 'func'. In fact, it doesn't matter if the active > state is the 1st time or other times, does it? What Alan wanted to say, I think, was that .runtime_post_resume() would have to be always identical, where func() need not be always the same function. Moreover, .runtime_post_resume() would _always_ be run after a device resume, while func() is run only _once_. > > not be made _every_ time the device resumes. > > Suppose the device is always resumed in the path(such as irq context), > the callback is still called every time. Yes, but what if you have _two_ code paths and you want to call different code as func() in each of them? > If the .runtime_post_resume is to be a one-time call, that is easy to do it. No, it isn't. > Also I am wondering why the callback shouldn't be called after resume > in sync context, and it may simplify implementation if the two contexts > (sync vs. async) are kept consistent. I have no idea what you're talking about. We actually have a callback that is run every time a device is resumed. It is called .runtime_idle(). Does it help, though? No, it doesn't. > >> Also, the 'func' should be per driver, not per device since only one > >> 'func' is enough for all same kind of devices driven by one same > >> driver. > > > > But what if the subsystem defines its own dev_pm_info structure? Then > > the driver's dev_pm_info will be ignored by the runtime PM core. All > > the subsystems would have to be changed. > > Suppose .runtime_post_resume is introduced, It is not going to be introduced, period. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 15:14 ` Ming Lei 2012-08-07 15:42 ` Alan Stern @ 2012-08-07 20:45 ` Rafael J. Wysocki 2012-08-08 2:02 ` Ming Lei 1 sibling, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-07 20:45 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Tuesday, August 07, 2012, Ming Lei wrote: > On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > >> Yes, I agree, but I don't think it may make .runtime_post_resume > >> not doable, do I? > > > > No more device PM callbacks, please. > > IMO, what the patch is doing is to introduce one callback which > is just called after .runtime_resume is completed, No, it is not a callback. It is a function to be run _once_ when the device is known to be active. It is not a member of a data type or anything like this. It's kind of disappointing that you don't see a difference between that and a callback. > and you want to move something out of previous .runtime_resume No, I don't. Where did you get that idea from? > and do it in another new callback to speedup resume, No, not to speed up resume. The idea is to allow drivers to run something when the resume is complete, so that they don't have to implement a "resume detection" logic or use .runtime_resume() to run things that don't belong there. > so it should be reasonable to introduce the .runtime_post_resume callback in > logic. No. This doesn't have anything to do with callbacks! If you want a new callback, you should specify what the role of this callback is, otherwise it is not well defined. I this case, though, what the role of func() is depends on the caller and most likely every driver would use it for something different. So no, I don't see how it can be a callback. > Also, the 'func' should be per driver, not per device since only one > 'func' is enough for all same kind of devices driven by one same > driver. It isn't per device! It is per _caller_. The fact that the pointer is stored _temporarily_ in struct device doesn't mean that it is per device and that it is a callback. From the struct device point of view it is _data_, not a member function. > > Besides, callbacks in struct dev_pm_ops are not only for drivers. > > All the current 3 runtime callbacks are for devices. If you mean > they can be defined in bus/power_domain/device_type, .runtime_post_resume > still can be defined there too. No, it wouldn't make _any_ _sense_ there, because its role there cannot be defined in any sane way. > >> > Also, "func" should not be stored in dev_pm_ops because it won't be a > >> > read-only value. > >> > >> Sorry, could you explain it in detail that why the 'func' > >> has to switch to multiple functions dynamically? I understand > >> one function is enough and sometimes it can be bypassed with > >> one flag(such as, ignore_post_resume is introduced in dev_pm_info) > >> set. Also, the driver can store the device specific states > >> in its own device instance to deal with different situations in the callback. > >> > >> If the idea is doable, we can save one pointer in 'struct device', > >> since the 'func' may not be used by more than 90% devices, also > >> have document benefit, even may simplify implementation of the > >> mechanism. > > > > And how many struct device objects there are for the one extra pointer to > > matter, let alone the fact that you want to replace it by one extra pointer > > somewhere else? > > For example, in the pandaboard(one omap4 based small system), follows > the count of device instances: > > [root@root]#dmesg | grep device_add | wc -l > 471 > > The above is just a simple configuration(no graphics, no video/video, only > console enabled) on Pandaboard. > > If the callback may be defined in dev_pm_info, I guess you mean struct dev_pm_ops, right? > not only memory can be saved, also there are other advantages described > before. So now please count how many struct dev_pm_ops objects there are on that system and compute the differece. And please note that drivers that don't use struct dev_pm_ops for power management will do that in the future. Also please note that the caller of pm_runtime_get_and_call() need not be a driver, at least in theory. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 20:45 ` Rafael J. Wysocki @ 2012-08-08 2:02 ` Ming Lei 2012-08-08 18:42 ` Alan Stern 2012-08-08 22:27 ` Rafael J. Wysocki 0 siblings, 2 replies; 89+ messages in thread From: Ming Lei @ 2012-08-08 2:02 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Wed, Aug 8, 2012 at 4:45 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > On Tuesday, August 07, 2012, Ming Lei wrote: >> On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: >> >> Yes, I agree, but I don't think it may make .runtime_post_resume >> >> not doable, do I? >> > >> > No more device PM callbacks, please. >> >> IMO, what the patch is doing is to introduce one callback which >> is just called after .runtime_resume is completed, > > No, it is not a callback. It is a function to be run _once_ when the device is > known to be active. It is not a member of a data type or anything like this. Looks it was said by Alan, not me, :-) "The documentation should explain that in some ways, "func" is like a workqueue callback routine:". See http://marc.info/?l=linux-usb&m=134426838507799&w=2 > > It's kind of disappointing that you don't see a difference between that and a > callback. > >> and you want to move something out of previous .runtime_resume > > No, I don't. Where did you get that idea from? If so, I am wondering why the 'func' can't be called in .runtime_resume directly, and follow the below inside caller at the same time? if (device is active or disabled) call func(device). > >> and do it in another new callback to speedup resume, > > No, not to speed up resume. The idea is to allow drivers to run something > when the resume is complete, so that they don't have to implement a "resume > detection" logic or use .runtime_resume() to run things that don't belong > there. Looks it was said by you, :-) "Unless your _driver_ callback is actually executed from within a PM domain callback, for example, and something else may be waiting for it to complete, so your data processing is adding latencies to some other threads. I'm not making that up, by the way, that really can happen." See http://marc.info/?l=linux-pm&m=134394271517527&w=2 Alan also said "Okay, those are valid reasons" for the idea. Except for this one, I don't see other obvious advantages about the patch. > >> so it should be reasonable to introduce the .runtime_post_resume callback in >> logic. > > No. This doesn't have anything to do with callbacks! > > If you want a new callback, you should specify what the role of this callback > is, otherwise it is not well defined. I this case, though, what the role of > func() is depends on the caller and most likely every driver would use it > for something different. So no, I don't see how it can be a callback. > >> Also, the 'func' should be per driver, not per device since only one >> 'func' is enough for all same kind of devices driven by one same >> driver. > > It isn't per device! It is per _caller_. The fact that the pointer is > stored _temporarily_ in struct device doesn't mean that it is per device > and that it is a callback. From the struct device point of view it is _data_, > not a member function. The fact is that it will become per-device one you store it in 'struct device'. Suppose one driver may drive 10000 same devices, the same data will be stored inside all the 10000 device instances, it is a good way to do it? Not mention 90% devices mayn't use the _temporarily_ data at all. > >> > Besides, callbacks in struct dev_pm_ops are not only for drivers. >> >> All the current 3 runtime callbacks are for devices. If you mean >> they can be defined in bus/power_domain/device_type, .runtime_post_resume >> still can be defined there too. > > No, it wouldn't make _any_ _sense_ there, because its role there cannot be > defined in any sane way. > >> >> > Also, "func" should not be stored in dev_pm_ops because it won't be a >> >> > read-only value. >> >> >> >> Sorry, could you explain it in detail that why the 'func' >> >> has to switch to multiple functions dynamically? I understand >> >> one function is enough and sometimes it can be bypassed with >> >> one flag(such as, ignore_post_resume is introduced in dev_pm_info) >> >> set. Also, the driver can store the device specific states >> >> in its own device instance to deal with different situations in the callback. >> >> >> >> If the idea is doable, we can save one pointer in 'struct device', >> >> since the 'func' may not be used by more than 90% devices, also >> >> have document benefit, even may simplify implementation of the >> >> mechanism. >> > >> > And how many struct device objects there are for the one extra pointer to >> > matter, let alone the fact that you want to replace it by one extra pointer >> > somewhere else? >> >> For example, in the pandaboard(one omap4 based small system), follows >> the count of device instances: >> >> [root@root]#dmesg | grep device_add | wc -l >> 471 >> >> The above is just a simple configuration(no graphics, no video/video, only >> console enabled) on Pandaboard. >> >> If the callback may be defined in dev_pm_info, > > I guess you mean struct dev_pm_ops, right? Sorry, it is a typo. > >> not only memory can be saved, also there are other advantages described >> before. > > So now please count how many struct dev_pm_ops objects there are on that system > and compute the differece. And please note that drivers that don't use > struct dev_pm_ops for power management will do that in the future. Most of dev_pm_ops stays inside module image, and not in ram. It is a bit difficult to get the count of all dev_pm_ops objects in ram since it is defined statically. For example, in USB subsystem, there are only 2 dev_pm_ops objects in RAM for a normal system, but there may have hundreds of usb devices in the system(usb_device, usb_interface, ep_device, ...). > > Also please note that the caller of pm_runtime_get_and_call() need not be > a driver, at least in theory. I admit it in theory, :-) Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-08 2:02 ` Ming Lei @ 2012-08-08 18:42 ` Alan Stern 2012-08-08 20:16 ` Rafael J. Wysocki 2012-08-08 22:27 ` Rafael J. Wysocki 1 sibling, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-08 18:42 UTC (permalink / raw) To: Ming Lei; +Cc: Rafael J. Wysocki, linux-pci, USB list, Linux PM list On Wed, 8 Aug 2012, Ming Lei wrote: > On Wed, Aug 8, 2012 at 4:45 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > On Tuesday, August 07, 2012, Ming Lei wrote: > >> On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > >> >> Yes, I agree, but I don't think it may make .runtime_post_resume > >> >> not doable, do I? > >> > > >> > No more device PM callbacks, please. > >> > >> IMO, what the patch is doing is to introduce one callback which > >> is just called after .runtime_resume is completed, > > > > No, it is not a callback. It is a function to be run _once_ when the device is > > known to be active. It is not a member of a data type or anything like this. > > Looks it was said by Alan, not me, :-) > > "The documentation should explain that in some ways, "func" is like a > workqueue callback routine:". > > See http://marc.info/?l=linux-usb&m=134426838507799&w=2 I didn't say it _was_ a callback; I said it was _like_ a callback in some ways. > If so, I am wondering why the 'func' can't be called in .runtime_resume > directly, and follow the below inside caller at the same time? > > if (device is active or disabled) > call func(device). That was my original suggestion. Rafael pointed out that having a single function call to do this would make it easier for driver writers to get it right. > > No, not to speed up resume. The idea is to allow drivers to run something > > when the resume is complete, so that they don't have to implement a "resume > > detection" logic or use .runtime_resume() to run things that don't belong > > there. > > Looks it was said by you, :-) > > "Unless your _driver_ callback is actually executed from within a PM domain > callback, for example, and something else may be waiting for it to complete, > so your data processing is adding latencies to some other threads. I'm not > making that up, by the way, that really can happen." > > See http://marc.info/?l=linux-pm&m=134394271517527&w=2 > > Alan also said "Okay, those are valid reasons" for the idea. Except for > this one, I don't see other obvious advantages about the patch. Those _are_ the two advantages: The runtime-resume method does nothing but bring the device back to full power; it doesn't do any other processing; It's easier than calling pm_runtime_get() followed by a test to see whether the device is active. > Suppose one driver may drive 10000 same devices, the same data will be > stored inside all the 10000 device instances, it is a good way to do it? If you've got a system with 10000 device instances, you can probably spare the memory needed to store these function pointers. But you're right that this is a disadvantage. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-08 18:42 ` Alan Stern @ 2012-08-08 20:16 ` Rafael J. Wysocki 2012-08-09 5:55 ` Ming Lei 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-08 20:16 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Wednesday, August 08, 2012, Alan Stern wrote: > On Wed, 8 Aug 2012, Ming Lei wrote: [...] > > If so, I am wondering why the 'func' can't be called in .runtime_resume > > directly, and follow the below inside caller at the same time? > > > > if (device is active or disabled) > > call func(device). > > That was my original suggestion. Rafael pointed out that having a > single function call to do this would make it easier for driver writers > to get it right. Not only would it be easier to get it right, in my opinion, but also in the example above func() may be called in some places where the driver may not want it to be called and which are very difficult to detect (like a resume from __device_suspend() during system suspend). Moreover, if the driver callback is not executed directly by the PM core, but instead it is executed by a subsystem or PM domain callback, there's no guarantee that the device _can_ be used for processing regular I/O before the driver callback returns (the subsystem callback may still need to do something _after_ that happens). So, this appears to be a matter of correctness too. > > > No, not to speed up resume. The idea is to allow drivers to run something > > > when the resume is complete, so that they don't have to implement a "resume > > > detection" logic or use .runtime_resume() to run things that don't belong > > > there. > > > > Looks it was said by you, :-) > > > > "Unless your _driver_ callback is actually executed from within a PM domain > > callback, for example, and something else may be waiting for it to complete, > > so your data processing is adding latencies to some other threads. I'm not > > making that up, by the way, that really can happen." > > > > See http://marc.info/?l=linux-pm&m=134394271517527&w=2 > > > > Alan also said "Okay, those are valid reasons" for the idea. Except for > > this one, I don't see other obvious advantages about the patch. > > Those _are_ the two advantages: > > The runtime-resume method does nothing but bring the device > back to full power; it doesn't do any other processing; > > It's easier than calling pm_runtime_get() followed by a test > to see whether the device is active. > > > Suppose one driver may drive 10000 same devices, the same data will be > > stored inside all the 10000 device instances, it is a good way to do it? > > If you've got a system with 10000 device instances, you can probably > spare the memory needed to store these function pointers. But you're > right that this is a disadvantage. Yes, it is in grand general, but that also is a matter of alignment and of the way the slab allocator works. For example, if every struct device object were stored at the beginning of a new memory page, then its size wouldn't matter a lot as long as it were smaller than PAGE_SIZE. I haven't checked the details, but I'm pretty sure that focusing on the size alone doesn't give us the whole picture here. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-08 20:16 ` Rafael J. Wysocki @ 2012-08-09 5:55 ` Ming Lei 2012-08-09 10:46 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-09 5:55 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Thu, Aug 9, 2012 at 4:16 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > On Wednesday, August 08, 2012, Alan Stern wrote: To be honest, I agree on the idea: The runtime-resume method does nothing but bring the device back to full power; it doesn't do any other processing, which should be done in 'func' or some kind of callback. I just think it is not good to introduce one extra field of 'func' in dev_pm_info which is embedded into struct device in the patch, see the reasons in the last part of the reply. >> That was my original suggestion. Rafael pointed out that having a >> single function call to do this would make it easier for driver writers >> to get it right. > > Not only would it be easier to get it right, in my opinion, but also in the > example above func() may be called in some places where the driver may not > want it to be called and which are very difficult to detect (like a resume > from __device_suspend() during system suspend). Moreover, if the driver IMO, func() does some driver specific things, which PM core shouldn't pay special attention to in theory. > callback is not executed directly by the PM core, but instead it is executed by > a subsystem or PM domain callback, there's no guarantee that the device _can_ > be used for processing regular I/O before the driver callback returns (the > subsystem callback may still need to do something _after_ that happens). driver->runtime_resume should be allowed to do I/O things after the device has been woken up inside driver callback, shouldn't it? If it isn't allowed, something wrong should have be reported before. > So, this appears to be a matter of correctness too. >> If you've got a system with 10000 device instances, you can probably >> spare the memory needed to store these function pointers. But you're >> right that this is a disadvantage. > > Yes, it is in grand general, but that also is a matter of alignment and of > the way the slab allocator works. For example, if every struct device > object were stored at the beginning of a new memory page, then its size > wouldn't matter a lot as long as it were smaller than PAGE_SIZE. > > I haven't checked the details, but I'm pretty sure that focusing on the size > alone doesn't give us the whole picture here. The allocation by kmalloc is not page aligned, and it is 2-power aligned, for example 16, 32, 64,..., also it is at least hardware L1 cache size aligned. Firstly, introduce one extra pointer in device may increase memory consume for device allocation, also it reflects one design drawback in the patch, see below. More importantly, the implementation violates some software design principle in object oriented design. The driver core takes much object oriented idea in its design and implementation, and introduces device / driver / bus class. One class is an abstraction of one kind of objects or instances with same attributes, so one class may include many objects, for example, usb_device(class) is abstraction for all usb devices, and there may have many many usb devices in a system, but only one usb_device structure defined. One specific driver class is a special class since it may only have one driver object , which is basically read only. In OO world, it might be called static class. Generally, one driver object serves one specific device class, instead of one device object. For example, usb_storage_driver is a driver object, which serves all usb mass storage devices which all belongs to usb mass storage class). The 'func' to be introduced is a function pointer, which should be driver related thing and should serve one specific device class in theory, and it shouldn't serve only one concrete device object, so it is not good to include it into 'struct device'. The only function pointer in struct device: void (*release)(struct device *dev) should be removed. All its users should convert to use device_type to define release handler for its 'device class', instead of device object. So suggest to improve it. Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-09 5:55 ` Ming Lei @ 2012-08-09 10:46 ` Rafael J. Wysocki 2012-08-09 10:55 ` Ming Lei 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-09 10:46 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Thursday, August 09, 2012, Ming Lei wrote: > On Thu, Aug 9, 2012 at 4:16 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > On Wednesday, August 08, 2012, Alan Stern wrote: > > To be honest, I agree on the idea: > > The runtime-resume method does nothing but bring the device > back to full power; it doesn't do any other processing, which > should be done in 'func' or some kind of callback. Good. :-) > I just think it is not good to introduce one extra field of 'func' in > dev_pm_info which is embedded into struct device in the patch, > see the reasons in the last part of the reply. > > >> That was my original suggestion. Rafael pointed out that having a > >> single function call to do this would make it easier for driver writers > >> to get it right. > > > > Not only would it be easier to get it right, in my opinion, but also in the > > example above func() may be called in some places where the driver may not > > want it to be called and which are very difficult to detect (like a resume > > from __device_suspend() during system suspend). Moreover, if the driver > > IMO, func() does some driver specific things, which PM core shouldn't pay > special attention to in theory. But also it shouldn't execute that code, right? > > callback is not executed directly by the PM core, but instead it is executed by > > a subsystem or PM domain callback, there's no guarantee that the device _can_ > > be used for processing regular I/O before the driver callback returns (the > > subsystem callback may still need to do something _after_ that happens). > > driver->runtime_resume should be allowed to do I/O things after > the device has been woken up inside driver callback, shouldn't it? If it > isn't allowed, something wrong should have be reported before. Well, the lack of reports doesn't mean there are no bugs. :-) People may actually see those bugs, but they don't report them or they report them as system suspend/resume bugs, for example. > > So, this appears to be a matter of correctness too. > > > >> If you've got a system with 10000 device instances, you can probably > >> spare the memory needed to store these function pointers. But you're > >> right that this is a disadvantage. > > > > Yes, it is in grand general, but that also is a matter of alignment and of > > the way the slab allocator works. For example, if every struct device > > object were stored at the beginning of a new memory page, then its size > > wouldn't matter a lot as long as it were smaller than PAGE_SIZE. > > > > I haven't checked the details, but I'm pretty sure that focusing on the size > > alone doesn't give us the whole picture here. > > The allocation by kmalloc is not page aligned, and it is 2-power > aligned, for example 16, 32, 64,..., also it is at least hardware > L1 cache size aligned. Sure, that's why I used the conditional above. And it doesn't mean I didn't have the point. > Firstly, introduce one extra pointer in device may increase memory > consume for device allocation, Yes, it does, which may or may not matter depending on the actual size of struct device and the CPU cache line size on the given machine, right? > also it reflects one design drawback in the patch, see below. > > More importantly, the implementation violates some software design > principle in object oriented design. It doesn't violate anything and you're just ignoring what you've been told. That makes discussing with you rather difficult, but I'll try again nevertheless. If you look at the actual patch I've just posted: https://patchwork.kernel.org/patch/1299781/ you can see that power.func is never run directly. Moreover, the pointer it contains is only used to run a function in pm_runtime_work() and note that pm_runtime_work() reads that pointer _twice_, because it may be changed in the meantime by a concurrent thread. All of this means what I've told you already at least once: power.func is _not_ _a_ _member_ _function_. IOW, if it were C++, power.func would still be a function pointer, not a method, because it is _data_, although its data type happens to be "void function taking a struct device pointer argument". It is a data field used to pass information to a work function, pm_runtime_work(), from a piece of code that schedules its execution, __pm_runtime_get_and_call(). See now? > The driver core takes much > object oriented idea in its design and implementation, and introduces > device / driver / bus class. One class is an abstraction of one kind of > objects or instances with same attributes, so one class may include > many objects, for example, usb_device(class) is abstraction for all usb > devices, and there may have many many usb devices in a system, but only > one usb_device structure defined. > > One specific driver class is a special class since it may only have one > driver object , which is basically read only. In OO world, it might be called > static class. > > Generally, one driver object serves one specific device class, instead > of one device object. For example, usb_storage_driver is a driver object, > which serves all usb mass storage devices which all belongs to usb mass > storage class). > > The 'func' to be introduced is a function pointer, which should be > driver related thing and should serve one specific device class in theory, > and it shouldn't serve only one concrete device object, so it is not good > to include it into 'struct device'. No. You're confusing function pointers with member functions. Yes, we use function pointers to store the addresses of member functions, because that's what we can do in C. Again, in C++ member functions would be methods, but we still might use function pointers for other purposes. Whether or not it is "elegant" or "clean" (or whatever you call it) function pointers for other purposes is a different matter and I think it is highly subjective. > The only function pointer in struct device: > > void (*release)(struct device *dev) > > should be removed. All its users should convert to use device_type to > define release handler for its 'device class', instead of device object. > > So suggest to improve it. What I want the callers to be able to do is "run this code right now if the device is operational or schedule the resume of it and run this code when it's been resumed". So, the pointer is used to tell the workqueue code which code to run (if any) when the device has been resumed. I don't want a "run this code every time the device is resumed" kind of thing, which I agree that a callback would be more suitable for. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-09 10:46 ` Rafael J. Wysocki @ 2012-08-09 10:55 ` Ming Lei 2012-08-09 19:41 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-09 10:55 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Thu, Aug 9, 2012 at 6:46 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > On Thursday, August 09, 2012, Ming Lei wrote: >> driver->runtime_resume should be allowed to do I/O things after >> the device has been woken up inside driver callback, shouldn't it? If it >> isn't allowed, something wrong should have be reported before. > > Well, the lack of reports doesn't mean there are no bugs. :-) > > People may actually see those bugs, but they don't report them or they > report them as system suspend/resume bugs, for example. Also, I am still wondering why subsystem PM callback need to do something after driver->runtime_resume completes, could you explain it? >> Firstly, introduce one extra pointer in device may increase memory >> consume for device allocation, > > Yes, it does, which may or may not matter depending on the actual size of > struct device and the CPU cache line size on the given machine, right? It may double memory allocation size in some cases. And it is very possible since there are so many device objects in system. > >> also it reflects one design drawback in the patch, see below. >> >> More importantly, the implementation violates some software design >> principle in object oriented design. > > It doesn't violate anything and you're just ignoring what you've been told. > That makes discussing with you rather difficult, but I'll try again > nevertheless. > > If you look at the actual patch I've just posted: > > https://patchwork.kernel.org/patch/1299781/ > > you can see that power.func is never run directly. Moreover, the pointer it > contains is only used to run a function in pm_runtime_work() and note that > pm_runtime_work() reads that pointer _twice_, because it may be changed in the > meantime by a concurrent thread. I have explained it before, it is enough to keep the pointer read only since driver can maintain its internal state in its specific device instance (for example, usb_interface objects) and decide what to do in 'func' for situations, right? Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-09 10:55 ` Ming Lei @ 2012-08-09 19:41 ` Rafael J. Wysocki 2012-08-10 3:19 ` Ming Lei 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-09 19:41 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Thursday, August 09, 2012, Ming Lei wrote: > On Thu, Aug 9, 2012 at 6:46 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > On Thursday, August 09, 2012, Ming Lei wrote: > > >> driver->runtime_resume should be allowed to do I/O things after > >> the device has been woken up inside driver callback, shouldn't it? If it > >> isn't allowed, something wrong should have be reported before. > > > > Well, the lack of reports doesn't mean there are no bugs. :-) > > > > People may actually see those bugs, but they don't report them or they > > report them as system suspend/resume bugs, for example. > > Also, I am still wondering why subsystem PM callback need to do > something after driver->runtime_resume completes, could you explain > it? It just isn't guaranteed that the subsystem callback won't do anything after driver->runtime_resume completion. I agree that it isn't likely to happen. > >> Firstly, introduce one extra pointer in device may increase memory > >> consume for device allocation, > > > > Yes, it does, which may or may not matter depending on the actual size of > > struct device and the CPU cache line size on the given machine, right? > > It may double memory allocation size in some cases. And it is very possible > since there are so many device objects in system. Numbers, please? If you don't have them, it's just waving your hands. > >> also it reflects one design drawback in the patch, see below. > >> > >> More importantly, the implementation violates some software design > >> principle in object oriented design. > > > > It doesn't violate anything and you're just ignoring what you've been told. > > That makes discussing with you rather difficult, but I'll try again > > nevertheless. > > > > If you look at the actual patch I've just posted: > > > > https://patchwork.kernel.org/patch/1299781/ > > > > you can see that power.func is never run directly. Moreover, the pointer it > > contains is only used to run a function in pm_runtime_work() and note that > > pm_runtime_work() reads that pointer _twice_, because it may be changed in the > > meantime by a concurrent thread. > > I have explained it before, it is enough to keep the pointer read only > since driver can maintain its internal state in its specific device instance > (for example, usb_interface objects) and decide what to do in 'func' > for situations, right? Yes, it is. I actually have a patch that does something similar (I'll post it shortly). Of course, it is based on the assumption that func() will always be the same pointer for the given driver, which doesn't seem to be proven, but perhaps it is sufficient. At least I'm not aware of use cases where it wouldn't be. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-09 19:41 ` Rafael J. Wysocki @ 2012-08-10 3:19 ` Ming Lei 2012-08-10 20:29 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Ming Lei @ 2012-08-10 3:19 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Fri, Aug 10, 2012 at 3:41 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > It just isn't guaranteed that the subsystem callback won't do anything > after driver->runtime_resume completion. I agree that it isn't likely > to happen. In fact, the subsystem callback should make sure that don't happen, see below comments on .runtime_resume: * @runtime_resume: Put the device into the fully active state in response to a * wakeup event generated by hardware or at the request of software. If * necessary, put the device into the full-power state and restore its * registers, so that it is fully operational. So once driver->runtime_resume completes, the device should be fully operational from the view of driver. > >> >> Firstly, introduce one extra pointer in device may increase memory >> >> consume for device allocation, >> > >> > Yes, it does, which may or may not matter depending on the actual size of >> > struct device and the CPU cache line size on the given machine, right? >> >> It may double memory allocation size in some cases. And it is very possible >> since there are so many device objects in system. > > Numbers, please? If you don't have them, it's just waving your hands. It is easily observed and proved. Suppose sizeof(struct foo_dev) is 508bytes, it will become 516bytes after your patch applies on 64bit arch, so ksize(foo_dev_ptr) will become 1024 and the memory consumption of the object is doubled. >> I have explained it before, it is enough to keep the pointer read only >> since driver can maintain its internal state in its specific device instance >> (for example, usb_interface objects) and decide what to do in 'func' >> for situations, right? > > Yes, it is. I actually have a patch that does something similar (I'll post it > shortly). I have seen your patch which moves the 'func' from device into device_driver. It is much better than before. > Of course, it is based on the assumption that func() will always be the same > pointer for the given driver, which doesn't seem to be proven, but perhaps > it is sufficient. At least I'm not aware of use cases where it wouldn't be. Since you have moved 'func' into device_driver, and you still thought the pointer can't be changed after it is set, so why not implement it as callback? IMO, it is a bit weird to just store a function pointer data(not for callback) in driver object, but anyway, it is better than before, :-) Thanks, -- Ming Lei ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-10 3:19 ` Ming Lei @ 2012-08-10 20:29 ` Rafael J. Wysocki 0 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-10 20:29 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Friday, August 10, 2012, Ming Lei wrote: > On Fri, Aug 10, 2012 at 3:41 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > > > It just isn't guaranteed that the subsystem callback won't do anything > > after driver->runtime_resume completion. I agree that it isn't likely > > to happen. > > In fact, the subsystem callback should make sure that don't happen, see > below comments on .runtime_resume: > > * @runtime_resume: Put the device into the fully active state in response to a > * wakeup event generated by hardware or at the request of software. If > * necessary, put the device into the full-power state and restore its > * registers, so that it is fully operational. > > So once driver->runtime_resume completes, the device should be fully operational > from the view of driver. This comment only applies literally to drivers whose callbacks are run directly by the PM core. If subsystems and/or PM domains are involved, the interactions between different layers of callbacks obviously have to be taken into account. Please note, however, that this comment doesn't say anything about processing I/O by the callback (hint: the callback is _not_ _supposed_ to do that). > >> >> Firstly, introduce one extra pointer in device may increase memory > >> >> consume for device allocation, > >> > > >> > Yes, it does, which may or may not matter depending on the actual size of > >> > struct device and the CPU cache line size on the given machine, right? > >> > >> It may double memory allocation size in some cases. And it is very possible > >> since there are so many device objects in system. > > > > Numbers, please? If you don't have them, it's just waving your hands. > > It is easily observed and proved. Suppose sizeof(struct foo_dev) is 508bytes, > it will become 516bytes after your patch applies on 64bit arch, so > ksize(foo_dev_ptr) > will become 1024 and the memory consumption of the object is doubled. I meant real numbers, not made-up ones. > >> I have explained it before, it is enough to keep the pointer read only > >> since driver can maintain its internal state in its specific device instance > >> (for example, usb_interface objects) and decide what to do in 'func' > >> for situations, right? > > > > Yes, it is. I actually have a patch that does something similar (I'll post it > > shortly). > > I have seen your patch which moves the 'func' from device into device_driver. > It is much better than before. Oh, thanks for letting me know. > > Of course, it is based on the assumption that func() will always be the same > > pointer for the given driver, which doesn't seem to be proven, but perhaps > > it is sufficient. At least I'm not aware of use cases where it wouldn't be. > > Since you have moved 'func' into device_driver, and you still thought the > pointer can't be changed after it is set, so why not implement it as callback? I don't understand what you mean. It _is_ a callback now in fact. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-08 2:02 ` Ming Lei 2012-08-08 18:42 ` Alan Stern @ 2012-08-08 22:27 ` Rafael J. Wysocki 1 sibling, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-08 22:27 UTC (permalink / raw) To: Ming Lei; +Cc: Alan Stern, linux-pci, USB list, Linux PM list On Wednesday, August 08, 2012, Ming Lei wrote: > On Wed, Aug 8, 2012 at 4:45 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > On Tuesday, August 07, 2012, Ming Lei wrote: > >> On Tue, Aug 7, 2012 at 7:23 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: [...] > > > >> and you want to move something out of previous .runtime_resume > > > > No, I don't. Where did you get that idea from? > > If so, I am wondering why the 'func' can't be called in .runtime_resume > directly, and follow the below inside caller at the same time? > > if (device is active or disabled) > call func(device). This was covered in my last reply to Alan. > >> and do it in another new callback to speedup resume, > > > > No, not to speed up resume. The idea is to allow drivers to run something > > when the resume is complete, so that they don't have to implement a "resume > > detection" logic or use .runtime_resume() to run things that don't belong > > there. > > Looks it was said by you, :-) > > "Unless your _driver_ callback is actually executed from within a PM domain > callback, for example, and something else may be waiting for it to complete, > so your data processing is adding latencies to some other threads. I'm not > making that up, by the way, that really can happen." > > See http://marc.info/?l=linux-pm&m=134394271517527&w=2 We were discussing specific pseudo-code in the documentation and you conveniently took the above out of context. Never mind. :-) I was trying to illustrate my point with a convincing example and I admit I could do better. Anyway the point was that the purpose of .runtime_resume() was not to process random I/O. Its purpose is to _resume_ a suspended device, no less, no more. Which the "so that they don't have to [...] use .runtime_resume() to run things that don't belong there." sentence above is about. So I've been saying the same thing all the time and it's never been specifically about speedup (or rather about latencies added by random I/O processing in drivers' runtime resume callbacks). > Alan also said "Okay, those are valid reasons" for the idea. Except for > this one, I don't see other obvious advantages about the patch. > > > > >> so it should be reasonable to introduce the .runtime_post_resume callback in > >> logic. > > > > No. This doesn't have anything to do with callbacks! > > > > If you want a new callback, you should specify what the role of this callback > > is, otherwise it is not well defined. I this case, though, what the role of > > func() is depends on the caller and most likely every driver would use it > > for something different. So no, I don't see how it can be a callback. > > > >> Also, the 'func' should be per driver, not per device since only one > >> 'func' is enough for all same kind of devices driven by one same > >> driver. > > > > It isn't per device! It is per _caller_. The fact that the pointer is > > stored _temporarily_ in struct device doesn't mean that it is per device > > and that it is a callback. From the struct device point of view it is _data_, > > not a member function. > > The fact is that it will become per-device one you store it in 'struct device'. > > Suppose one driver may drive 10000 same devices, Do you have any specific example of that? If not, then please don't make up arguments. > the same data will be stored inside all the 10000 device instances, it is a > good way to do it? > > Not mention 90% devices mayn't use the _temporarily_ data at all. It may be unused just as well as an additional callback pointer in a driver object. [...] > > > > So now please count how many struct dev_pm_ops objects there are on that system > > and compute the differece. And please note that drivers that don't use > > struct dev_pm_ops for power management will do that in the future. > > Most of dev_pm_ops stays inside module image, and not in ram. Care to explain? I'm not sure I understand the above correctly. > It is a bit difficult to get the count of all dev_pm_ops objects in ram > since it is defined statically. Still, they are occupying memory, aren't they? So you really can't tell the difference between storing pointers in device driver objects and struct device objects. > For example, in USB subsystem, there are only 2 dev_pm_ops > objects in RAM for a normal system, but there may have hundreds of > usb devices in the system(usb_device, usb_interface, ep_device, ...). Yes, USB is kind of exceptional, but also this means that your "let's put that pointer into struct dev_pm_ops" idea won't work for USB drivers, precisely because they don't use struct dev_pm_ops objects. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-05 15:26 ` Rafael J. Wysocki 2012-08-06 13:30 ` Ming Lei @ 2012-08-06 15:48 ` Alan Stern 2012-08-06 20:30 ` Rafael J. Wysocki 1 sibling, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-06 15:48 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Sun, 5 Aug 2012, Rafael J. Wysocki wrote: > I don't really think we'll need to store func_sync in dev->power. At least > I don't see a reason to do that at the moment. You're right; I wasn't thinking straight. > I also think that func_sync() would have to be called if runtime PM is > disabled for the given device, so that callers don't have to check that > condition themselves. Yes. > What about the appended experimental patch? For now, I think it would be best to start with a single func argument. If it turns out that anyone really needs to have two separate arguments, the single-argument form can be reimplemented on top of the two-argument form easily enough. > @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de > goto out; > } > > +void rpm_queue_up_resume(struct device *dev) > +{ > + dev->power.request = RPM_REQ_RESUME; > + if (!dev->power.request_pending) { > + dev->power.request_pending = true; > + queue_work(pm_wq, &dev->power.work); > + } > +} > + > /** > * rpm_resume - Carry out runtime resume of given device. > * @dev: Device to resume. > @@ -524,7 +533,9 @@ static int rpm_resume(struct device *dev > * rather than cancelling it now only to restart it again in the near > * future. > */ > - dev->power.request = RPM_REQ_NONE; > + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) > + dev->power.request = RPM_REQ_NONE; > + > if (!dev->power.timer_autosuspends) > pm_runtime_deactivate_timer(dev); > > @@ -533,6 +544,12 @@ static int rpm_resume(struct device *dev > goto out; > } > > + if (dev->power.func && (rpmflags & RPM_ASYNC)) { > + rpm_queue_up_resume(dev); > + retval = 0; > + goto out; > + } > + > if (dev->power.runtime_status == RPM_RESUMING > || dev->power.runtime_status == RPM_SUSPENDING) { > DEFINE_WAIT(wait); All those changes (and some of the following ones) are symptoms of a basic mistake in this approach. The idea of this new feature is to call "func" as soon as we know the device is at full power, no matter how it got there. That means we should call it near the end of rpm_resume() (just before the rpm_idle() call), not from within pm_runtime_work(). Doing it this way will be more efficient and (I think) will remove some races. > @@ -877,6 +903,48 @@ int __pm_runtime_resume(struct device *d > } > EXPORT_SYMBOL_GPL(__pm_runtime_resume); > > +int pm_runtime_get_and_call(struct device *dev, void (*func)(struct device *), > + void (*func_async)(struct device *)) > +{ > + unsigned long flags; > + int ret; > + > + atomic_inc(&dev->power.usage_count); > + > + spin_lock_irqsave(&dev->power.lock, flags); > + > + ret = dev->power.runtime_error; > + if (ret) { > + func = NULL; > + goto out; > + } > + > + if (dev->power.runtime_status != RPM_ACTIVE > + && dev->power.disable_depth == 0) > + func = NULL; > + > + if (!func && func_async) { > + if (dev->power.func) { > + ret = -EAGAIN; > + goto out; > + } else { > + dev->power.func = func_async; > + } > + } The logic here is kind of hard to follow. It will be simpler when there's only one "func": If the status is RPM_ACTIVE or disable_depth > 0 then call "func" directly. Otherwise save "func" in dev.power and do an async resume. Some more things: In __pm_runtime_set_status(), if power.func is set then I think we should call it if the new status is ACTIVE. Likwise at the end of rpm_suspend(), if the suspend fails. There should be an invariant: Whenever the status is RPM_ACTIVE, power.func must be NULL. pm_runtime_barrier() should always clear power.func, even if the rpm_resume() call fails. The documentation should explain that in some ways, "func" is like a workqueue callback routine: Subsystems and drivers have to be careful to make sure that it can't be invoked after the device is unbound. A safe way to do this is to call pm_runtime_barrier() from within the driver's .remove() routine, after making sure that pm_runtime_get_and_call() won't be invoked any more. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-06 15:48 ` Alan Stern @ 2012-08-06 20:30 ` Rafael J. Wysocki 2012-08-07 12:28 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-06 20:30 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Monday, August 06, 2012, Alan Stern wrote: > On Sun, 5 Aug 2012, Rafael J. Wysocki wrote: [...] > > > What about the appended experimental patch? > > For now, I think it would be best to start with a single func argument. > If it turns out that anyone really needs to have two separate > arguments, the single-argument form can be reimplemented on top of the > two-argument form easily enough. All right. > > @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de > > goto out; > > } > > > > +void rpm_queue_up_resume(struct device *dev) > > +{ > > + dev->power.request = RPM_REQ_RESUME; > > + if (!dev->power.request_pending) { > > + dev->power.request_pending = true; > > + queue_work(pm_wq, &dev->power.work); > > + } > > +} > > + > > /** > > * rpm_resume - Carry out runtime resume of given device. > > * @dev: Device to resume. > > @@ -524,7 +533,9 @@ static int rpm_resume(struct device *dev > > * rather than cancelling it now only to restart it again in the near > > * future. > > */ > > - dev->power.request = RPM_REQ_NONE; > > + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) > > + dev->power.request = RPM_REQ_NONE; > > + > > if (!dev->power.timer_autosuspends) > > pm_runtime_deactivate_timer(dev); > > > > @@ -533,6 +544,12 @@ static int rpm_resume(struct device *dev > > goto out; > > } > > > > + if (dev->power.func && (rpmflags & RPM_ASYNC)) { > > + rpm_queue_up_resume(dev); > > + retval = 0; > > + goto out; > > + } > > + > > if (dev->power.runtime_status == RPM_RESUMING > > || dev->power.runtime_status == RPM_SUSPENDING) { > > DEFINE_WAIT(wait); > > All those changes (and some of the following ones) are symptoms of a > basic mistake in this approach. Every time you say something like this (i.e. liks someone who knows better) I kind of feel like being under attach, which I hope is not your intention. Never mind. :-) Those changes are there for different reasons rather unrelated to the way func() is being called, so let me explain. First, rpm_queue_up_resume() is introduced, because the code it contains will have to be called in two different places. At least I don't see how to avoid that without increasing the code complexity too much. Second, the following change in rpm_resume() - dev->power.request = RPM_REQ_NONE; + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) + dev->power.request = RPM_REQ_NONE; is made to prevent rpm_resume() from canceling the execution of func() queued up by an earlier pm_runtime_get_and_call(). I believe it is necessary. Finally, this change in rpm_resume(): + if (dev->power.func && (rpmflags & RPM_ASYNC)) { + rpm_queue_up_resume(dev); + retval = 0; + goto out; + } is not strictly necessary if pm_runtime_get_and_call() is modified to run rpm_queue_up_resume() directly, like in the new version of the patch which is appended. This reduces the number of checks overall, so perhaps it's better. > The idea of this new feature is to > call "func" as soon as we know the device is at full power, no matter > how it got there. Yes, it is so. > That means we should call it near the end of > rpm_resume() (just before the rpm_idle() call), not from within > pm_runtime_work(). > > Doing it this way will be more efficient and (I think) will remove > some races. Except that func() shouldn't be executed under dev->power.lock, which makes it rather difficult to call it from rpm_resume(). Or at least it seems so. Moreover, it should be called after we've changed the status to RPM_ACTIVE _and_ dropped the lock. Besides, I'd like to know what races you're referring to (perhaps you're seeing some more of them than I am). > > @@ -877,6 +903,48 @@ int __pm_runtime_resume(struct device *d > > } > > EXPORT_SYMBOL_GPL(__pm_runtime_resume); > > > > +int pm_runtime_get_and_call(struct device *dev, void (*func)(struct device *), > > + void (*func_async)(struct device *)) > > +{ > > + unsigned long flags; > > + int ret; > > + > > + atomic_inc(&dev->power.usage_count); > > + > > + spin_lock_irqsave(&dev->power.lock, flags); > > + > > + ret = dev->power.runtime_error; > > + if (ret) { > > + func = NULL; > > + goto out; > > + } > > + > > + if (dev->power.runtime_status != RPM_ACTIVE > > + && dev->power.disable_depth == 0) > > + func = NULL; > > + > > + if (!func && func_async) { > > + if (dev->power.func) { > > + ret = -EAGAIN; > > + goto out; > > + } else { > > + dev->power.func = func_async; > > + } > > + } > > The logic here is kind of hard to follow. It will be simpler when > there's only one "func": > > If the status is RPM_ACTIVE or disable_depth > 0 then > call "func" directly. > > Otherwise save "func" in dev.power and do an async resume. Yeah. But do not run func() under power.lock, right? > Some more things: > > In __pm_runtime_set_status(), if power.func is set then I think we > should call it if the new status is ACTIVE. __pm_runtime_set_status() only works if power.disable_depth > 0, in which case func() will be called synchronously. Now, if someone does pm_runtime_get_and_call() immediately followed by pm_runtime_disable() (perhaps from a different thread), then __pm_runtime_disable() will resume the device, so it's better to call func() from there if set, I think. And clear power.func afterwards. > Likwise at the end of rpm_suspend(), if the suspend fails. The only way by which power.func can be different from NULL at that point is when the work item queued up by pm_runtime_get_and_call() runs after rpm_suspend() has changed the status to RPM_SUSPENDING. However in that case the rpm_resume(dev, 0) in pm_runtime_work() will wait for the suspend to complete (or fail) and func() will be run when it returns. > There should be an invariant: Whenever the status is RPM_ACTIVE, > power.func must be NULL. Well, maybe so, but I don't see why right now. > pm_runtime_barrier() should always clear power.func, even if the > rpm_resume() call fails. Wouldn't it be better to wait for func() to be run? > The documentation should explain that in some ways, "func" is like a > workqueue callback routine: Subsystems and drivers have to be careful > to make sure that it can't be invoked after the device is unbound. A > safe way to do this is to call pm_runtime_barrier() from within the > driver's .remove() routine, after making sure that > pm_runtime_get_and_call() won't be invoked any more. Sure. The appended patch doesn't contain any changes in __pm_runtime_disable() or pm_runtime_barrier(), but you are right that they are necessary. Thanks, Rafael --- drivers/base/power/runtime.c | 98 ++++++++++++++++++++++++++++++++++++++----- include/linux/pm.h | 1 include/linux/pm_runtime.h | 11 ++++ 3 files changed, 99 insertions(+), 11 deletions(-) Index: linux/drivers/base/power/runtime.c =================================================================== --- linux.orig/drivers/base/power/runtime.c +++ linux/drivers/base/power/runtime.c @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de goto out; } +void rpm_queue_up_resume(struct device *dev) +{ + dev->power.request = RPM_REQ_RESUME; + if (!dev->power.request_pending) { + dev->power.request_pending = true; + queue_work(pm_wq, &dev->power.work); + } +} + /** * rpm_resume - Carry out runtime resume of given device. * @dev: Device to resume. @@ -519,12 +528,18 @@ static int rpm_resume(struct device *dev goto out; /* - * Other scheduled or pending requests need to be canceled. Small - * optimization: If an autosuspend timer is running, leave it running - * rather than cancelling it now only to restart it again in the near - * future. + * Other scheduled or pending requests need to be canceled. If the + * execution of a function is queued up along with a resume request, + * do not cancel it. + */ + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) + dev->power.request = RPM_REQ_NONE; + + /* + * Small optimization: If an autosuspend timer is running, leave it + * running rather than cancelling it now only to restart it again in the + * near future. */ - dev->power.request = RPM_REQ_NONE; if (!dev->power.timer_autosuspends) pm_runtime_deactivate_timer(dev); @@ -591,11 +606,7 @@ static int rpm_resume(struct device *dev /* Carry out an asynchronous or a synchronous resume. */ if (rpmflags & RPM_ASYNC) { - dev->power.request = RPM_REQ_RESUME; - if (!dev->power.request_pending) { - dev->power.request_pending = true; - queue_work(pm_wq, &dev->power.work); - } + rpm_queue_up_resume(dev); retval = 0; goto out; } @@ -691,6 +702,7 @@ static int rpm_resume(struct device *dev static void pm_runtime_work(struct work_struct *work) { struct device *dev = container_of(work, struct device, power.work); + void (*func)(struct device *) = NULL; enum rpm_request req; spin_lock_irq(&dev->power.lock); @@ -715,12 +727,24 @@ static void pm_runtime_work(struct work_ rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); break; case RPM_REQ_RESUME: - rpm_resume(dev, RPM_NOWAIT); + func = dev->power.func; + if (func) { + dev->power.func = NULL; + pm_runtime_get_noresume(dev); + rpm_resume(dev, 0); + } else { + rpm_resume(dev, RPM_NOWAIT); + } break; } out: spin_unlock_irq(&dev->power.lock); + + if (func) { + func(dev); + pm_runtime_put(dev); + } } /** @@ -877,6 +901,58 @@ int __pm_runtime_resume(struct device *d } EXPORT_SYMBOL_GPL(__pm_runtime_resume); +int pm_runtime_get_and_call(struct device *dev, void (*func)(struct device *)) +{ + unsigned long flags; + bool sync = false; + int ret; + + atomic_inc(&dev->power.usage_count); + + spin_lock_irqsave(&dev->power.lock, flags); + + ret = dev->power.runtime_error; + if (ret) + goto out; + + sync = dev->power.runtime_status == RPM_ACTIVE + || dev->power.disable_depth > 0; + + if (!sync) { + if (dev->power.func) { + ret = -EAGAIN; + goto out; + } else { + dev->power.func = func; + } + } + + /* + * The approach here is the same as in rpm_suspend(): autosuspend timers + * will be activated shortly anyway, so it is pointless to cancel them + * now. + */ + if (!dev->power.timer_autosuspends) + pm_runtime_deactivate_timer(dev); + + if (sync) + dev->power.request = RPM_REQ_NONE; + else + rpm_queue_up_resume(dev); + + out: + spin_unlock_irqrestore(&dev->power.lock, flags); + + if (sync) { + if (func) + func(dev); + + return 1; + } + + return ret; +} + /** * __pm_runtime_set_status - Set runtime PM status of a device. * @dev: Device to handle. Index: linux/include/linux/pm.h =================================================================== --- linux.orig/include/linux/pm.h +++ linux/include/linux/pm.h @@ -547,6 +547,7 @@ struct dev_pm_info { unsigned long suspended_jiffies; unsigned long accounting_timestamp; struct dev_pm_qos_request *pq_req; + void (*func)(struct device *); #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ struct pm_qos_constraints *constraints; Index: linux/include/linux/pm_runtime.h =================================================================== --- linux.orig/include/linux/pm_runtime.h +++ linux/include/linux/pm_runtime.h @@ -47,6 +47,8 @@ extern void pm_runtime_set_autosuspend_d extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev); extern void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns); +extern int pm_runtime_get_and_call(struct device *dev, + void (*func)(struct device *)); static inline bool pm_children_suspended(struct device *dev) { @@ -150,6 +152,15 @@ static inline void pm_runtime_set_autosu static inline unsigned long pm_runtime_autosuspend_expiration( struct device *dev) { return 0; } +static inline int pm_runtime_get_and_call(struct device *dev, + void (*func)(struct device *)) +{ + if (func) + func(dev); + + return 1; +} + #endif /* !CONFIG_PM_RUNTIME */ static inline int pm_runtime_idle(struct device *dev) ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-06 20:30 ` Rafael J. Wysocki @ 2012-08-07 12:28 ` Rafael J. Wysocki 2012-08-07 17:15 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-07 12:28 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Monday, August 06, 2012, Rafael J. Wysocki wrote: > On Monday, August 06, 2012, Alan Stern wrote: > > On Sun, 5 Aug 2012, Rafael J. Wysocki wrote: > [...] > > > > > What about the appended experimental patch? > > > > For now, I think it would be best to start with a single func argument. > > If it turns out that anyone really needs to have two separate > > arguments, the single-argument form can be reimplemented on top of the > > two-argument form easily enough. > > All right. > > > > @@ -484,6 +484,15 @@ static int rpm_suspend(struct device *de > > > goto out; > > > } > > > > > > +void rpm_queue_up_resume(struct device *dev) > > > +{ > > > + dev->power.request = RPM_REQ_RESUME; > > > + if (!dev->power.request_pending) { > > > + dev->power.request_pending = true; > > > + queue_work(pm_wq, &dev->power.work); > > > + } > > > +} > > > + > > > /** > > > * rpm_resume - Carry out runtime resume of given device. > > > * @dev: Device to resume. > > > @@ -524,7 +533,9 @@ static int rpm_resume(struct device *dev > > > * rather than cancelling it now only to restart it again in the near > > > * future. > > > */ > > > - dev->power.request = RPM_REQ_NONE; > > > + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) > > > + dev->power.request = RPM_REQ_NONE; > > > + > > > if (!dev->power.timer_autosuspends) > > > pm_runtime_deactivate_timer(dev); > > > > > > @@ -533,6 +544,12 @@ static int rpm_resume(struct device *dev > > > goto out; > > > } > > > > > > + if (dev->power.func && (rpmflags & RPM_ASYNC)) { > > > + rpm_queue_up_resume(dev); > > > + retval = 0; > > > + goto out; > > > + } > > > + > > > if (dev->power.runtime_status == RPM_RESUMING > > > || dev->power.runtime_status == RPM_SUSPENDING) { > > > DEFINE_WAIT(wait); > > > > All those changes (and some of the following ones) are symptoms of a > > basic mistake in this approach. > > Every time you say something like this (i.e. liks someone who knows better) s/liks/like/ > I kind of feel like being under attach, which I hope is not your intention. s/attach/attack/ Two typos in one sentence, I guess it could have been worse ... > Never mind. :-) > > Those changes are there for different reasons rather unrelated to the way > func() is being called, so let me explain. > > First, rpm_queue_up_resume() is introduced, because the code it contains will > have to be called in two different places. At least I don't see how to avoid > that without increasing the code complexity too much. > > Second, the following change in rpm_resume() > > - dev->power.request = RPM_REQ_NONE; > + if (dev->power.request != RPM_REQ_RESUME || !dev->power.func) > + dev->power.request = RPM_REQ_NONE; > > is made to prevent rpm_resume() from canceling the execution of func() queued > up by an earlier pm_runtime_get_and_call(). I believe it is necessary. > > Finally, this change in rpm_resume(): > > + if (dev->power.func && (rpmflags & RPM_ASYNC)) { > + rpm_queue_up_resume(dev); > + retval = 0; > + goto out; > + } > > is not strictly necessary if pm_runtime_get_and_call() is modified to run > rpm_queue_up_resume() directly, like in the new version of the patch which is > appended. This reduces the number of checks overall, so perhaps it's better. > > > The idea of this new feature is to > > call "func" as soon as we know the device is at full power, no matter > > how it got there. > > Yes, it is so. > > > That means we should call it near the end of > > rpm_resume() (just before the rpm_idle() call), not from within > > pm_runtime_work(). > > > > Doing it this way will be more efficient and (I think) will remove > > some races. > > Except that func() shouldn't be executed under dev->power.lock, which makes it > rather difficult to call it from rpm_resume(). Or at least it seems so. > > Moreover, it should be called after we've changed the status to RPM_ACTIVE > _and_ dropped the lock. So we could drop the lock right before returning, execute func() and acquire the lock once again, but then func() might be executed by any thread that happened to resume the device. In that case the caller of pm_runtime_get_and_call() would have to worry about locks that such threads might acquire and it would have to make sure that func() didn't try to acquire them too. That may not be a big deal, but if func() is executed by pm_runtime_work(), that issue simply goes away. Then, however, there's another issue: what should happen if pm_runtime_get_and_call() finds that it cannot execute func() right away, so it queues up resume and the execution of it, in the meantime some other thread resumes the device synchronously and pm_runtime_get_and_call() is run again. I think in that case func() should be executed synchronously and the one waiting for execution should be canceled. The alternative would be to return -EAGAIN from pm_runtime_get_and_call() and expect the caller to cope with that, which isn't too attractive. This actually is analogous to the case when pm_runtime_get_and_call() sees that power.func is not NULL. In my experimental patches it returned -EAGAIN in that case, but perhaps it's better to replace the existing power.func with the new one. Then, by doing pm_runtime_get_and_call(dev, NULL) we can ensure that either the previous func() has run already or it will never run, which may be useful. Well, I guess I need to prepare a new experimantal patch. :-) I'll send it in a new thread I think. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 12:28 ` Rafael J. Wysocki @ 2012-08-07 17:15 ` Alan Stern 2012-08-07 21:31 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-07 17:15 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Tue, 7 Aug 2012, Rafael J. Wysocki wrote: > > > All those changes (and some of the following ones) are symptoms of a > > > basic mistake in this approach. > > > > Every time you say something like this (i.e. liks someone who knows better) > > s/liks/like/ > > > I kind of feel like being under attach, which I hope is not your intention. > > s/attach/attack/ Sorry; you're right. It's all too easy to get very arrogant in email messages. I'll try not to attack so strongly in the future. > > > The idea of this new feature is to > > > call "func" as soon as we know the device is at full power, no matter > > > how it got there. > > > > Yes, it is so. Incidentally, that sentence is the justification for the invariance condition mentioned later. power.func should be called as soon as we know the device is at full power; therefore when the status changes to RPM_ACTIVE it should be called and then cleared (if it was set), and it should never get set while the status is RPM_ACTIVE. Therefore it should never be true that power.func is set _and_ the status is RPM_ACTIVE. > > > That means we should call it near the end of > > > rpm_resume() (just before the rpm_idle() call), not from within > > > pm_runtime_work(). > > > > > > Doing it this way will be more efficient and (I think) will remove > > > some races. > > > > Except that func() shouldn't be executed under dev->power.lock, which makes it > > rather difficult to call it from rpm_resume(). Or at least it seems so. > > > > Moreover, it should be called after we've changed the status to RPM_ACTIVE > > _and_ dropped the lock. > > So we could drop the lock right before returning, execute func() and acquire > the lock once again, Yes; that's what I had in mind. We already do something similar when calling pm_runtime_put(parent). > but then func() might be executed by any thread that > happened to resume the device. In that case the caller of > pm_runtime_get_and_call() would have to worry about locks that such threads > might acquire and it would have to make sure that func() didn't try to acquire > them too. That may not be a big deal, but if func() is executed by > pm_runtime_work(), that issue simply goes away. But then you have to worry about races between pm_runtime_resume() and the workqueue. If the device is resumed by some other thread, it could be suspended again before "func" is called. > Then, however, there's another issue: what should happen if > pm_runtime_get_and_call() finds that it cannot execute func() right away, > so it queues up resume and the execution of it, in the meantime some other > thread resumes the device synchronously and pm_runtime_get_and_call() is > run again. I think in that case func() should be executed synchronously > and the one waiting for execution should be canceled. The alternative > would be to return -EAGAIN from pm_runtime_get_and_call() and expect the > caller to cope with that, which isn't too attractive. > > This actually is analogous to the case when pm_runtime_get_and_call() > sees that power.func is not NULL. In my experimental patches it returned > -EAGAIN in that case, but perhaps it's better to replace the existing > power.func with the new one. Then, by doing pm_runtime_get_and_call(dev, NULL) > we can ensure that either the previous func() has run already or it will never > run, which may be useful. A good point. I agree that pm_runtime_get_and_call() should always overwrite the existing power.func value. There are a couple of other issues remaining. What's the best approach when disable_count > 0? My feeling is that we should still rely on power.runtime_status as the best approximation to the device's state, so we shouldn't call "func" directly unless the status is already RPM_ACTIVE. If the status is something else, we can't queue an async resume request. So we just set power.func and return. Eventually the driver will either call pm_runtime_set_active() or pm_runtime_enable() followed by pm_runtime_resume(), at which time we would call power.func. Also, what should happen when power.runtime_error is set? The same as when disable_depth > 0? You mentioned that pm_runtime_disable() does a resume if there's a pending resume request. I had forgotten about this. It worries me, because subsystems use code sequences like this: pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); in their system resume routines (in fact, we advise them to do so in the Documentation file). Now, it is unlikely for a resume request to be pending during system sleep, but it doesn't seem to be impossible. When there is such a pending request, the pm_runtime_disable() call will try to do a runtime resume at a time when the device has just been restored to full power. That's not good. Probably this pattern occurs in few enough places that we could go through and fix them all. But how? Should there be a new function: pm_adjust_runtime_status_after_system_resume()? Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-07 17:15 ` Alan Stern @ 2012-08-07 21:31 ` Rafael J. Wysocki 0 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-07 21:31 UTC (permalink / raw) To: Alan Stern; +Cc: Ming Lei, linux-pci, USB list, Linux PM list On Tuesday, August 07, 2012, Alan Stern wrote: > On Tue, 7 Aug 2012, Rafael J. Wysocki wrote: > > > > > All those changes (and some of the following ones) are symptoms of a > > > > basic mistake in this approach. > > > > > > Every time you say something like this (i.e. liks someone who knows better) > > > > s/liks/like/ > > > > > I kind of feel like being under attach, which I hope is not your intention. > > > > s/attach/attack/ > > Sorry; you're right. It's all too easy to get very arrogant in email > messages. I'll try not to attack so strongly in the future. Thanks! > > > > The idea of this new feature is to > > > > call "func" as soon as we know the device is at full power, no matter > > > > how it got there. > > > > > > Yes, it is so. > > Incidentally, that sentence is the justification for the invariance > condition mentioned later. :-) > power.func should be called as soon as we > know the device is at full power; therefore when the status changes to > RPM_ACTIVE it should be called and then cleared (if it was set), and it > should never get set while the status is RPM_ACTIVE. Therefore it > should never be true that power.func is set _and_ the status is > RPM_ACTIVE. I guess with the patch I've just sent: http://marc.info/?l=linux-pm&m=134437366811066&w=4 it's almost the case, except when a synchronous resume happens before the work item scheduled by __pm_runtime_get_and_call() is run. However, I don't think it is a problem in that case, because the device won't be suspended before the execution of that work item starts (rpm_check_suspend_allowed() will see that power.request_pending is set and that power.request is RPM_REQ_RESUME, so it will return -EAGAIN). > > > > That means we should call it near the end of > > > > rpm_resume() (just before the rpm_idle() call), not from within > > > > pm_runtime_work(). > > > > > > > > Doing it this way will be more efficient and (I think) will remove > > > > some races. > > > > > > Except that func() shouldn't be executed under dev->power.lock, which makes it > > > rather difficult to call it from rpm_resume(). Or at least it seems so. > > > > > > Moreover, it should be called after we've changed the status to RPM_ACTIVE > > > _and_ dropped the lock. > > > > So we could drop the lock right before returning, execute func() and acquire > > the lock once again, > > Yes; that's what I had in mind. We already do something similar when > calling pm_runtime_put(parent). Yes, we do. However, I still don't think it's really safe to call func() from rpm_resume(), because it may be run synchronously from a context quite unrelated to the caller of __pm_runtime_get_and_call() (for example, from the pm_runtime_barrier() in __device_suspend()). > > but then func() might be executed by any thread that > > happened to resume the device. In that case the caller of > > pm_runtime_get_and_call() would have to worry about locks that such threads > > might acquire and it would have to make sure that func() didn't try to acquire > > them too. That may not be a big deal, but if func() is executed by > > pm_runtime_work(), that issue simply goes away. > > But then you have to worry about races between pm_runtime_resume() and > the workqueue. If the device is resumed by some other thread, it > could be suspended again before "func" is called. No, it can't, if the device's usage count is incremented before dropping power.lock after rpm_resume(dev, 0) has returned. > > Then, however, there's another issue: what should happen if > > pm_runtime_get_and_call() finds that it cannot execute func() right away, > > so it queues up resume and the execution of it, in the meantime some other > > thread resumes the device synchronously and pm_runtime_get_and_call() is > > run again. I think in that case func() should be executed synchronously > > and the one waiting for execution should be canceled. The alternative > > would be to return -EAGAIN from pm_runtime_get_and_call() and expect the > > caller to cope with that, which isn't too attractive. > > > > This actually is analogous to the case when pm_runtime_get_and_call() > > sees that power.func is not NULL. In my experimental patches it returned > > -EAGAIN in that case, but perhaps it's better to replace the existing > > power.func with the new one. Then, by doing pm_runtime_get_and_call(dev, NULL) > > we can ensure that either the previous func() has run already or it will never > > run, which may be useful. > > A good point. I agree that pm_runtime_get_and_call() should always > overwrite the existing power.func value. > > There are a couple of other issues remaining. > > What's the best approach when disable_count > 0? My feeling is that we > should still rely on power.runtime_status as the best approximation to > the device's state, so we shouldn't call "func" directly unless the > status is already RPM_ACTIVE. Well, that's one possibility. In that case, though, the caller may want to run func() regardless of whether or not runtime PM is enabled for the given device and that would require some serious trickery. For this reason, in the newest patch (http://marc.info/?l=linux-pm&m=134437366811066&w=4) the caller can choose what to do. > If the status is something else, we > can't queue an async resume request. So we just set power.func and > return. Eventually the driver will either call pm_runtime_set_active() > or pm_runtime_enable() followed by pm_runtime_resume(), at which time > we would call power.func. > > Also, what should happen when power.runtime_error is set? The same as > when disable_depth > 0? I think so. > You mentioned that pm_runtime_disable() does a resume if there's a > pending resume request. I had forgotten about this. It worries me, > because subsystems use code sequences like this: > > pm_runtime_disable(dev); > pm_runtime_set_active(dev); > pm_runtime_enable(dev); > > in their system resume routines (in fact, we advise them to do so in > the Documentation file). Now, it is unlikely for a resume request to > be pending during system sleep, but it doesn't seem to be impossible. > When there is such a pending request, the pm_runtime_disable() call > will try to do a runtime resume at a time when the device has just been > restored to full power. That's not good. Well, they should do __pm_runtime_disable(dev, false), then. > Probably this pattern occurs in few enough places that we could go > through and fix them all. But how? Should there be a new function: > pm_adjust_runtime_status_after_system_resume()? I think the above would suffice. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 2:20 ` Alan Stern 2012-08-03 3:37 ` Ming Lei @ 2012-08-03 14:05 ` Alan Stern 2012-08-04 20:08 ` Rafael J. Wysocki 2012-08-04 19:35 ` Rafael J. Wysocki 2 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-03 14:05 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list On Thu, 2 Aug 2012, Alan Stern wrote: > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > > I don't know about that -- the logic involved in doing the processing > > > within the resume callback isn't terribly complicated. At least, not > > > much more complicated than the logic involved in setting up a custom > > > work routine as you suggest. > > > > That's why I had the idea of pm_request_resume_and_call(dev, func) > > described in this message: > > > > http://marc.info/?l=linux-usb&m=134377126804170&w=4 > > > > although perheps it would be better to call it something like > > pm_runtime_async_resume_and_call(dev, func). > > Hmmm. You'd probably want a version that does a "get" at the same > time. I suppose you would call func directly if the device was already > resumed, without going through the workqueue? > > Yes, I agree this would be a better interface then pm_runtime_get. A few problems: What happens if a system sleep begins after pm_runtime_async_resume_and_call() but before the runtime resume? When the system wakes up, the device will be back at full power without ever executing a runtime PM call. Then how will func get invoked? What happens if the driver is unbound after pm_runtime_async_resume_and_call() but before the runtime resume? The When the runtime resume occurs, func will be invoked -- and the driver might not even be in memory any more. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 14:05 ` Alan Stern @ 2012-08-04 20:08 ` Rafael J. Wysocki 2012-08-04 20:42 ` Alan Stern 0 siblings, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 20:08 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Friday, August 03, 2012, Alan Stern wrote: > On Thu, 2 Aug 2012, Alan Stern wrote: > > > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > > > > I don't know about that -- the logic involved in doing the processing > > > > within the resume callback isn't terribly complicated. At least, not > > > > much more complicated than the logic involved in setting up a custom > > > > work routine as you suggest. > > > > > > That's why I had the idea of pm_request_resume_and_call(dev, func) > > > described in this message: > > > > > > http://marc.info/?l=linux-usb&m=134377126804170&w=4 > > > > > > although perheps it would be better to call it something like > > > pm_runtime_async_resume_and_call(dev, func). > > > > Hmmm. You'd probably want a version that does a "get" at the same > > time. I suppose you would call func directly if the device was already > > resumed, without going through the workqueue? > > > > Yes, I agree this would be a better interface then pm_runtime_get. > > A few problems: Which are good points. :-) > What happens if a system sleep begins after > pm_runtime_async_resume_and_call() but before the runtime resume? When > the system wakes up, the device will be back at full power without ever > executing a runtime PM call. Then how will func get invoked? The pm_runtime_barrier() at the beginning of __device_suspend() guarantees that if there's a resume request pending at this point, the resume will be carried out. I think we can modify rpm_resume() to return only after func() is executed, so there shouldn't be a problem with that particular case. > What happens if the driver is unbound after > pm_runtime_async_resume_and_call() but before the runtime resume? The > When the runtime resume occurs, func will be invoked -- and the driver > might not even be in memory any more. We have no protection against that at the moment, but then there is no guarantee that the driver's runtime PM callbacks won't be run after it's been unbound. Perhaps we should run pm_runtime_barrier() before executing .remove() in __device_release_driver() (and perhaps run pm_runtime_idle() afterwards in case the subsystem or PM domain knows how to power down the device even if there's no driver) and expect .remove() to clean up? Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 20:08 ` Rafael J. Wysocki @ 2012-08-04 20:42 ` Alan Stern 2012-08-04 20:59 ` Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-08-04 20:42 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: linux-pci, USB list, Linux PM list On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > What happens if a system sleep begins after > > pm_runtime_async_resume_and_call() but before the runtime resume? When > > the system wakes up, the device will be back at full power without ever > > executing a runtime PM call. Then how will func get invoked? > > The pm_runtime_barrier() at the beginning of __device_suspend() guarantees > that if there's a resume request pending at this point, the resume will be > carried out. I think we can modify rpm_resume() to return only after func() > is executed, so there shouldn't be a problem with that particular case. A resume request can get added to the workqueue after __device_suspend() runs, in which case the problem will still exist. Should pm_runtime_set_active() call func (if such a call is pending)? > > What happens if the driver is unbound after > > pm_runtime_async_resume_and_call() but before the runtime resume? The > > When the runtime resume occurs, func will be invoked -- and the driver > > might not even be in memory any more. > > We have no protection against that at the moment, but then there is no > guarantee that the driver's runtime PM callbacks won't be run after > it's been unbound. True. We have been relying on the subsystem to handle this race, but obviously that's no good if the callback is directly to the driver. I don't see any way to fix this in the PM core. > Perhaps we should run pm_runtime_barrier() before executing .remove() > in __device_release_driver() We already do pm_runtime_get_sync() and pm_runtime_put_sync(). I'm not sure how necessary those calls really are ... but pm_runtime_barrier() would be redundant. > (and perhaps run pm_runtime_idle() afterwards > in case the subsystem or PM domain knows how to power down the device even if > there's no driver) and expect .remove() to clean up? I can't think of anything wrong with calling pm_runtime_idle() at the end of __device_release_driver(). Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-04 20:42 ` Alan Stern @ 2012-08-04 20:59 ` Rafael J. Wysocki 0 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 20:59 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Saturday, August 04, 2012, Alan Stern wrote: > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote: > > > > What happens if a system sleep begins after > > > pm_runtime_async_resume_and_call() but before the runtime resume? When > > > the system wakes up, the device will be back at full power without ever > > > executing a runtime PM call. Then how will func get invoked? > > > > The pm_runtime_barrier() at the beginning of __device_suspend() guarantees > > that if there's a resume request pending at this point, the resume will be > > carried out. I think we can modify rpm_resume() to return only after func() > > is executed, so there shouldn't be a problem with that particular case. > > A resume request can get added to the workqueue after > __device_suspend() runs, in which case the problem will still exist. In theory. But the question is who's going to add that request, since the driver's (and possibly subsystem's/PM domain's) .suspend() callbacks will be run by __device_suspend() and we can expect those to ensure certain level of consistency. Anyway, today we'll have the same problem with a runtime resume request queued up during system suspend (after __device_suspend() has run). > Should pm_runtime_set_active() call func (if such a call is pending)? > > > > What happens if the driver is unbound after > > > pm_runtime_async_resume_and_call() but before the runtime resume? The > > > When the runtime resume occurs, func will be invoked -- and the driver > > > might not even be in memory any more. > > > > We have no protection against that at the moment, but then there is no > > guarantee that the driver's runtime PM callbacks won't be run after > > it's been unbound. > > True. We have been relying on the subsystem to handle this race, but > obviously that's no good if the callback is directly to the driver. I > don't see any way to fix this in the PM core. Me neither. > > Perhaps we should run pm_runtime_barrier() before executing .remove() > > in __device_release_driver() > > We already do pm_runtime_get_sync() and pm_runtime_put_sync(). I'm not > sure how necessary those calls really are ... They are, because some platforms do some unusual things in their platform bus type notifiers. > but pm_runtime_barrier() would be redundant. > > > (and perhaps run pm_runtime_idle() afterwards > > in case the subsystem or PM domain knows how to power down the device even if > > there's no driver) and expect .remove() to clean up? > > I can't think of anything wrong with calling pm_runtime_idle() at the > end of __device_release_driver(). Yeah. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) 2012-08-03 2:20 ` Alan Stern 2012-08-03 3:37 ` Ming Lei 2012-08-03 14:05 ` Alan Stern @ 2012-08-04 19:35 ` Rafael J. Wysocki 2 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-08-04 19:35 UTC (permalink / raw) To: Alan Stern; +Cc: linux-pci, USB list, Linux PM list On Friday, August 03, 2012, Alan Stern wrote: > On Thu, 2 Aug 2012, Rafael J. Wysocki wrote: > > > > I don't know about that -- the logic involved in doing the processing > > > within the resume callback isn't terribly complicated. At least, not > > > much more complicated than the logic involved in setting up a custom > > > work routine as you suggest. > > > > That's why I had the idea of pm_request_resume_and_call(dev, func) > > described in this message: > > > > http://marc.info/?l=linux-usb&m=134377126804170&w=4 > > > > although perheps it would be better to call it something like > > pm_runtime_async_resume_and_call(dev, func). > > Hmmm. You'd probably want a version that does a "get" at the same > time. I suppose you would call func directly if the device was already > resumed, without going through the workqueue? Yes. > Yes, I agree this would be a better interface then pm_runtime_get. OK > > > > Well, that shouldn't need the is_suspended flag at all, methinks, and the > > > > reason it does need it is because it uses pm_runtime_get(). > > > > > > Not so. Consider your scheme. When starting an I/O request, you call > > > pm_runtime_get_noresume() and then check to see if the device is > > > active, say by calling pm_runtime_suspended(). Suppose at that moment > > > the suspend callback has just finished and has released the private > > > spinlock. The device's status is still RPM_SUSPENDING, so > > > pm_runtime_suspended() returns 0 and you try to carry out the I/O. > > > > > > To fix this problem you have to synchronize the status checking with > > > the suspend/resume operations. This means the status changes have to > > > occur under the protection of the private lock, which means a private > > > flag is needed. > > > > What about checking if the status is RPM_ACTIVE under dev->power.lock? > > That's what rpm_resume() does, more or less. > > That wouldn't solve the race described above. > > > > > Moreover, > > > > processing requests in the resume callback is not something I'd recommend > > > > to anyone, because that's going to happen when the status of the device > > > > is RPM_RESUMING, we're holding a reference on the parent (if there's one) etc. > > > > > > I don't see any problem with that. The parent's child_count will be > > > incremented while the requests are being processed regardless. And if > > > you've been waiting for the device to resume in order to carry out some > > > processing, within the resume callback is the logical place to do the > > > work. > > > > Unless your _driver_ callback is actually executed from within a PM domain > > callback, for example, and something else may be waiting for it to complete, > > so your data processing is adding latencies to some other threads. I'm not > > making that up, by the way, that really can happen. > > > > And what if you are a parent waited for by a child to resume so that _it_ > > can process its data? Would you still want to process your data in the > > resume callback in that case? > > Okay, those are valid reasons. (Although a device handling I/O > requests isn't likely to have a child with its own independent I/O > handling.) I agree that this isn't very likely in practice. > > > I suppose we could keep pm_runtime_get_sync as is, and just change > > > pm_runtime_get to pm_runtime_get_async (and likewise for _put). That > > > could reduce the confusion during the changeover. > > > > Changing pm_runtime_get() to pm_runtime_get_async() would be an improvement, > > although pm_runtime_get_but_do_not_resume_immediately() might even be better. > > Or even pm_runtime_get_but_do_not_access_hardware_when_it_returns(). ;-) > > > > I see no reason to have any of those things, though. Yes, they _may_ be > > useful to someone knowing the runtime PM core internals to save a few lines > > of code in some places, but generally they lead people to make serious mistakes > > that tend to be difficult to debug. For this very reason pm_runtime_get() is a > > bad interface and I wish we hadn't introduced it at all. Even if we give it > > a more descriptive name, it won't be much better. > > > > And note how that doesn't apply to the pm_runtime_put*() family. After all, > > doing pm_runtime_put() instead of pm_runtime_put_sync() will never lead to > > accessing registers of a suspended device. > > All right. But I still think "pm_runtime_put_async" is better than > "pm_runtime_put". At least it forces people to think about what > they're doing. I agree. My current plan is to provide a better alternative interface, then to change the name of "pm_runtime_put" to "pm_runtime_put_async" and to document that it's going to be deprecated in future. Thanks, Rafael ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-29 14:55 ` Alan Stern 2012-07-29 19:18 ` Rafael J. Wysocki @ 2012-07-29 20:12 ` Jassi Brar 2012-07-29 21:44 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Jassi Brar @ 2012-07-29 20:12 UTC (permalink / raw) To: Alan Stern Cc: Rafael J. Wysocki, Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Sun, Jul 29, 2012 at 8:25 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > For me there's also an issue of style: If you do a synchronous get then it > looks odd not to do a synchronous put. My feeling has always been that > the async routines are for use in non-process contexts, where the sync > routines can't be used. Using them just to return a little more > quickly is a foreign idea. > Another way of looking at it is - I need h/w to be active in order to proceed so I call get_sync but I don't care if the h/w is not put down immediately after I am done using it. So the put could be relaxed/async - At best, we could avoid an unnecessary suspend-resume cycle which could be expensive power and time wise. At worst, we return a bit quicker. Or so do I think. ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure 2012-07-29 20:12 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Jassi Brar @ 2012-07-29 21:44 ` Alan Stern 0 siblings, 0 replies; 89+ messages in thread From: Alan Stern @ 2012-07-29 21:44 UTC (permalink / raw) To: Jassi Brar Cc: Rafael J. Wysocki, Huang Ying, Bjørn Mork, huang ying, Zheng Yan, Bjorn Helgaas, linux-pci, linux-usb On Mon, 30 Jul 2012, Jassi Brar wrote: > On Sun, Jul 29, 2012 at 8:25 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > > > For me there's also an issue of style: If you do a synchronous get then it > > looks odd not to do a synchronous put. My feeling has always been that > > the async routines are for use in non-process contexts, where the sync > > routines can't be used. Using them just to return a little more > > quickly is a foreign idea. > > > Another way of looking at it is - I need h/w to be active in order to > proceed so I call get_sync but I don't care if the h/w is not put down > immediately after I am done using it. So the put could be > relaxed/async - At best, we could avoid an unnecessary suspend-resume > cycle which could be expensive power and time wise. At worst, we > return a bit quicker. Or so do I think. If the reason for the choice is to opportunistically delay suspending, there are better ways of doing it: pm_schedule_suspend, pm_runtime_put_autosuspend. Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() 2012-07-25 13:30 ` huang ying 2012-07-25 13:58 ` Bjørn Mork @ 2012-07-25 19:51 ` Rafael J. Wysocki 2012-07-25 20:02 ` Alan Stern 1 sibling, 1 reply; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-25 19:51 UTC (permalink / raw) To: Bjorn Helgaas Cc: huang ying, Bjørn Mork, Huang Ying, Zheng Yan, linux-pci, linux-usb, Alan Stern, Linux PM list If a PCI device is put into D3_cold by acpi_bus_set_power(), the message printed by acpi_pci_set_power_state() says that its power state has been changed to D4, which doesn't make sense. In turn, if the device is put into D3_hot, the message says just "D3" without specifying which variant of D3 it is. Fix that by using an array of state names corresponding to the PCI device power states instead of building the state name from the numeric value corresponding to the given state directly. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/pci/pci-acpi.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) Index: linux/drivers/pci/pci-acpi.c =================================================================== --- linux.orig/drivers/pci/pci-acpi.c +++ linux/drivers/pci/pci-acpi.c @@ -265,9 +265,17 @@ static int acpi_pci_set_power_state(stru error = acpi_bus_set_power(handle, state_conv[state]); } - if (!error) - dev_printk(KERN_INFO, &dev->dev, - "power state changed by ACPI to D%d\n", state); + if (!error) { + static const char *state_name[] = { + [PCI_D0] = "D0", + [PCI_D1] = "D1", + [PCI_D2] = "D2", + [PCI_D3hot] = "D3hot", + [PCI_D3cold] = "D3cold" + }; + dev_info(&dev->dev, "power state changed by ACPI to %s\n", + state_name[state]); + } return error; } ^ permalink raw reply [flat|nested] 89+ messages in thread
* Re: [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() 2012-07-25 19:51 ` [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() Rafael J. Wysocki @ 2012-07-25 20:02 ` Alan Stern 2012-07-25 20:48 ` [PATCH][update] " Rafael J. Wysocki 0 siblings, 1 reply; 89+ messages in thread From: Alan Stern @ 2012-07-25 20:02 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Bjorn Helgaas, huang ying, Bjørn Mork, Huang Ying, Zheng Yan, linux-pci, linux-usb, Linux PM list On Wed, 25 Jul 2012, Rafael J. Wysocki wrote: > > If a PCI device is put into D3_cold by acpi_bus_set_power(), > the message printed by acpi_pci_set_power_state() says that its > power state has been changed to D4, which doesn't make sense. > In turn, if the device is put into D3_hot, the message says just > "D3" without specifying which variant of D3 it is. > > Fix that by using an array of state names corresponding to the > PCI device power states instead of building the state name from > the numeric value corresponding to the given state directly. > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > --- > drivers/pci/pci-acpi.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > Index: linux/drivers/pci/pci-acpi.c > =================================================================== > --- linux.orig/drivers/pci/pci-acpi.c > +++ linux/drivers/pci/pci-acpi.c > @@ -265,9 +265,17 @@ static int acpi_pci_set_power_state(stru > error = acpi_bus_set_power(handle, state_conv[state]); > } > > - if (!error) > - dev_printk(KERN_INFO, &dev->dev, > - "power state changed by ACPI to D%d\n", state); > + if (!error) { > + static const char *state_name[] = { > + [PCI_D0] = "D0", > + [PCI_D1] = "D1", > + [PCI_D2] = "D2", > + [PCI_D3hot] = "D3hot", > + [PCI_D3cold] = "D3cold" > + }; > + dev_info(&dev->dev, "power state changed by ACPI to %s\n", > + state_name[state]); > + } How about using the pci_power_name macro defined in include/linux/pci.h instead? Alan Stern ^ permalink raw reply [flat|nested] 89+ messages in thread
* [PATCH][update] PCI / PM: Fix messages printed by acpi_pci_set_power_state() 2012-07-25 20:02 ` Alan Stern @ 2012-07-25 20:48 ` Rafael J. Wysocki 0 siblings, 0 replies; 89+ messages in thread From: Rafael J. Wysocki @ 2012-07-25 20:48 UTC (permalink / raw) To: Alan Stern, Bjorn Helgaas Cc: huang ying, Bjørn Mork, Huang Ying, Zheng Yan, linux-pci, linux-usb, Linux PM list On Wednesday, July 25, 2012, Alan Stern wrote: > On Wed, 25 Jul 2012, Rafael J. Wysocki wrote: > > > > > If a PCI device is put into D3_cold by acpi_bus_set_power(), > > the message printed by acpi_pci_set_power_state() says that its > > power state has been changed to D4, which doesn't make sense. > > In turn, if the device is put into D3_hot, the message says just > > "D3" without specifying which variant of D3 it is. > > > > Fix that by using an array of state names corresponding to the > > PCI device power states instead of building the state name from > > the numeric value corresponding to the given state directly. > > > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > > --- > > drivers/pci/pci-acpi.c | 14 +++++++++++--- > > 1 file changed, 11 insertions(+), 3 deletions(-) > > > > Index: linux/drivers/pci/pci-acpi.c > > =================================================================== > > --- linux.orig/drivers/pci/pci-acpi.c > > +++ linux/drivers/pci/pci-acpi.c > > @@ -265,9 +265,17 @@ static int acpi_pci_set_power_state(stru > > error = acpi_bus_set_power(handle, state_conv[state]); > > } > > > > - if (!error) > > - dev_printk(KERN_INFO, &dev->dev, > > - "power state changed by ACPI to D%d\n", state); > > + if (!error) { > > + static const char *state_name[] = { > > + [PCI_D0] = "D0", > > + [PCI_D1] = "D1", > > + [PCI_D2] = "D2", > > + [PCI_D3hot] = "D3hot", > > + [PCI_D3cold] = "D3cold" > > + }; > > + dev_info(&dev->dev, "power state changed by ACPI to %s\n", > > + state_name[state]); > > + } > > How about using the pci_power_name macro defined in > include/linux/pci.h instead? That's even better, I forgot that the macro was there. :-) Updated patch follows. Thanks, Rafael --- From: Rafael J. Wysocki <rjw@sisk.pl> Subject: PCI / PM: Fix messages printed by acpi_pci_set_power_state() If a PCI device is put into D3_cold by acpi_bus_set_power(), the message printed by acpi_pci_set_power_state() says that its power state has been changed to D4, which doesn't make sense. In turn, if the device is put into D3_hot, the message simply says "D3" without specifying the variant of the D3 state. Fix this by using the pci_power_name() macro for printing the state name instead of building it from the numeric value corresponding to the given state directly. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/pci/pci-acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux/drivers/pci/pci-acpi.c =================================================================== --- linux.orig/drivers/pci/pci-acpi.c +++ linux/drivers/pci/pci-acpi.c @@ -266,8 +266,8 @@ static int acpi_pci_set_power_state(stru } if (!error) - dev_printk(KERN_INFO, &dev->dev, - "power state changed by ACPI to D%d\n", state); + dev_info(&dev->dev, "power state changed by ACPI to %s\n", + pci_power_name(state)); return error; } ^ permalink raw reply [flat|nested] 89+ messages in thread
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2012-07-25 4:08 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Bjørn Mork
2012-07-25 4:34 ` Huang Ying
2012-07-25 9:58 ` Bjørn Mork
2012-07-25 13:30 ` huang ying
2012-07-25 13:58 ` Bjørn Mork
2012-07-25 18:56 ` Rafael J. Wysocki
2012-07-25 20:02 ` Rafael J. Wysocki
2012-07-25 22:36 ` Bjørn Mork
2012-07-26 2:38 ` Huang Ying
2012-07-26 2:38 ` Huang Ying
2012-07-26 8:54 ` Huang Ying
2012-07-26 10:35 ` Bjørn Mork
2012-07-26 11:02 ` Bjørn Mork
2012-07-26 12:04 ` Bjørn Mork
2012-07-26 15:03 ` Alan Stern
2012-07-26 16:24 ` Bjørn Mork
2012-07-27 5:35 ` Huang Ying
2012-07-27 9:11 ` Bjørn Mork
2012-07-30 3:15 ` Huang Ying
2012-07-30 8:08 ` Bjørn Mork
2012-07-30 13:31 ` huang ying
2012-07-30 16:57 ` Bjørn Mork
2012-07-31 0:22 ` Huang Ying
2012-07-30 14:19 ` Alan Stern
2012-07-31 0:24 ` Huang Ying
2012-07-31 3:18 ` Huang Ying
2012-07-31 17:07 ` Alan Stern
2012-07-27 15:03 ` Alan Stern
2012-07-27 19:11 ` Rafael J. Wysocki
2012-07-27 19:39 ` Alan Stern
2012-07-27 19:54 ` Rafael J. Wysocki
2012-07-28 16:12 ` Alan Stern
2012-07-28 20:26 ` Rafael J. Wysocki
2012-07-28 21:12 ` Alan Stern
2012-07-29 13:55 ` Rafael J. Wysocki
2012-07-29 14:55 ` Alan Stern
2012-07-29 19:18 ` Rafael J. Wysocki
2012-07-31 20:31 ` Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) Rafael J. Wysocki
2012-07-31 21:05 ` Alan Stern
2012-07-31 21:34 ` Rafael J. Wysocki
2012-07-31 21:49 ` Rafael J. Wysocki
2012-08-01 14:36 ` Alan Stern
2012-08-01 21:24 ` Rafael J. Wysocki
2012-08-02 20:16 ` Alan Stern
2012-08-02 21:26 ` Rafael J. Wysocki
2012-08-03 2:20 ` Alan Stern
2012-08-03 3:37 ` Ming Lei
2012-08-03 14:28 ` Alan Stern
2012-08-04 19:47 ` Rafael J. Wysocki
2012-08-04 20:25 ` Alan Stern
2012-08-04 20:48 ` Rafael J. Wysocki
2012-08-04 20:48 ` Alan Stern
2012-08-04 21:15 ` Rafael J. Wysocki
2012-08-04 22:13 ` Alan Stern
2012-08-05 15:26 ` Rafael J. Wysocki
2012-08-06 13:30 ` Ming Lei
2012-08-06 14:47 ` Alan Stern
2012-08-07 1:35 ` Ming Lei
2012-08-07 11:23 ` Rafael J. Wysocki
2012-08-07 15:14 ` Ming Lei
2012-08-07 15:42 ` Alan Stern
2012-08-07 16:30 ` Ming Lei
2012-08-07 20:57 ` Rafael J. Wysocki
2012-08-07 20:45 ` Rafael J. Wysocki
2012-08-08 2:02 ` Ming Lei
2012-08-08 18:42 ` Alan Stern
2012-08-08 20:16 ` Rafael J. Wysocki
2012-08-09 5:55 ` Ming Lei
2012-08-09 10:46 ` Rafael J. Wysocki
2012-08-09 10:55 ` Ming Lei
2012-08-09 19:41 ` Rafael J. Wysocki
2012-08-10 3:19 ` Ming Lei
2012-08-10 20:29 ` Rafael J. Wysocki
2012-08-08 22:27 ` Rafael J. Wysocki
2012-08-06 15:48 ` Alan Stern
2012-08-06 20:30 ` Rafael J. Wysocki
2012-08-07 12:28 ` Rafael J. Wysocki
2012-08-07 17:15 ` Alan Stern
2012-08-07 21:31 ` Rafael J. Wysocki
2012-08-03 14:05 ` Alan Stern
2012-08-04 20:08 ` Rafael J. Wysocki
2012-08-04 20:42 ` Alan Stern
2012-08-04 20:59 ` Rafael J. Wysocki
2012-08-04 19:35 ` Rafael J. Wysocki
2012-07-29 20:12 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Jassi Brar
2012-07-29 21:44 ` Alan Stern
2012-07-25 19:51 ` [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() Rafael J. Wysocki
2012-07-25 20:02 ` Alan Stern
2012-07-25 20:48 ` [PATCH][update] " Rafael J. Wysocki
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.