Re: PCI trouble on mvebu (Turris Omnia)

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Bjorn Helgaas <helgaas@kernel.org> writes:

> [+cc Pali, Marek, Thomas, Jason]
>
> On Wed, Oct 28, 2020 at 04:40:00PM +0000, ™֟☻̭҇ Ѽ ҉ ® wrote:
>> On 28/10/2020 16:08, Toke Høiland-Jørgensen wrote:
>> > Bjorn Helgaas <helgaas@kernel.org> writes:
>> > > On Wed, Oct 28, 2020 at 02:36:13PM +0100, Toke Høiland-Jørgensen wrote:
>> > > > Toke Høiland-Jørgensen <toke@redhat.com> writes:
>> > > > > Bjorn Helgaas <helgaas@kernel.org> writes:
>> > > > > 
>> > > > > > [+cc vtolkm]
>> > > > > > 
>> > > > > > On Tue, Oct 27, 2020 at 04:43:20PM +0100, Toke Høiland-Jørgensen wrote:
>> > > > > > > Hi everyone
>> > > > > > > 
>> > > > > > > I'm trying to get a mainline kernel to run on my Turris Omnia, and am
>> > > > > > > having some trouble getting the PCI bus to work correctly. Specifically,
>> > > > > > > I'm running a 5.10-rc1 kernel (torvalds/master as of this moment), with
>> > > > > > > the resource request fix[0] applied on top.
>> > > > > > > 
>> > > > > > > The kernel boots fine, and the patch in [0] makes the PCI devices show
>> > > > > > > up. But I'm still getting initialisation errors like these:
>> > > > > > > 
>> > > > > > > [    1.632709] pci 0000:01:00.0: BAR 0: error updating (0xe0000004 != 0xffffffff)
>> > > > > > > [    1.632714] pci 0000:01:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
>> > > > > > > [    1.632745] pci 0000:02:00.0: BAR 0: error updating (0xe0200004 != 0xffffffff)
>> > > > > > > [    1.632750] pci 0000:02:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
>> > > > > > > 
>> > > > > > > and the WiFi drivers fail to initialise with what appears to me to be
>> > > > > > > errors related to the bus rather than to the drivers themselves:
>> > > > > > > 
>> > > > > > > [    3.509878] ath: phy0: Mac Chip Rev 0xfffc0.f is not supported by this driver
>> > > > > > > [    3.517049] ath: phy0: Unable to initialize hardware; initialization status: -95
>> > > > > > > [    3.524473] ath9k 0000:01:00.0: Failed to initialize device
>> > > > > > > [    3.530081] ath9k: probe of 0000:01:00.0 failed with error -95
>> > > > > > > [    3.536012] ath10k_pci 0000:02:00.0: of_irq_parse_pci: failed with rc=134
>> > > > > > > [    3.543049] pci 0000:00:02.0: enabling device (0140 -> 0142)
>> > > > > > > [    3.548735] ath10k_pci 0000:02:00.0: can't change power state from D3hot to D0 (config space inaccessible)
>> > > > > > > [    3.588592] ath10k_pci 0000:02:00.0: failed to wake up device : -110
>> > > > > > > [    3.595098] ath10k_pci: probe of 0000:02:00.0 failed with error -110
>> > > > > > > 
>> > > > > > > lspci looks OK, though:
>> > > > > > > 
>> > > > > > > # lspci
>> > > > > > > 00:01.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>> > > > > > > 00:02.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>> > > > > > > 00:03.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>> > > > > > > 01:00.0 Network controller: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
>> > > > > > > 02:00.0 Network controller: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter (rev ff)
>> > > > > > > 
>> > > > > > > Does anyone have any clue what could be going on here? Is this a bug, or
>> > > > > > > did I miss something in my config or other initialisation? I've tried
>> > > > > > > with both the stock u-boot distributed with the board, and with an
>> > > > > > > upstream u-boot from latest master; doesn't seem to make any different.
>> > > > > > Can you try turning off CONFIG_PCIEASPM?  We had a similar recent
>> > > > > > report at https://bugzilla.kernel.org/show_bug.cgi?id=209833 but I
>> > > > > > don't think we have a fix yet.
>> > > > > Yes! Turning that off does indeed help! Thanks a bunch :)
>> > > > > 
>> > > > > You mention that bisecting this would be helpful - I can try that
>> > > > > tomorrow; any idea when this was last working?
>> > > > OK, so I tried to bisect this, but, erm, I couldn't find a working
>> > > > revision to start from? I went all the way back to 4.10 (which is the
>> > > > first version to include the device tree file for the Omnia), and even
>> > > > on that, the wireless cards were failing to initialise with ASPM
>> > > > enabled...
>> > > I have no personal experience with this device; all I know is that the
>> > > bugzilla suggests that it worked in v5.4, which isn't much help.
>> > > 
>> > > Possibly the apparent regression was really a .config change, i.e.,
>> > > CONFIG_PCIEASPM was disabled in the v5.4 kernel vtolkm@ tested and it
>> > > "worked" but got enabled later and it started failing?
>> > Yeah, I suspect so. The OpenWrt config disables CONFIG_PCIEASPM by
>> > default and only turns it on for specific targets. So I guess that it's
>> > most likely that this has never worked...
>> > 
>> > > Maybe the debug patch below would be worth trying to see if it makes
>> > > any difference?  If it *does* help, try omitting the first hunk to see
>> > > if we just need to apply the quirk_enable_clear_retrain_link() quirk.
>> > Tried, doesn't help...
>> > 
>> > -Toke
>> 
>> Found this patch
>> 
>> https://github.com/openwrt/openwrt/blob/7c0496f29bed87326f1bf591ca25ace82373cfc7/target/linux/mvebu/patches-5.4/405-PCI-aardvark-Improve-link-training.patch
>> 
>> that mentions the Compex WLE900VX card, which reading the lspci verbose
>> output from the bugtracker seems to the device being troubled.
>
> Interesting.  Indeed, the Compex WLE900VX card seems to have the
> Qualcomm Atheros QCA9880 on it, and it looks like Toke's system has
> the same device in it.
>
> The patch you mention (https://git.kernel.org/linus/43fc679ced18) is
> for aardvark, so of course doesn't help mvebu.
>
> PCIe hardware is supposed to automatically negotiate the highest link
> speed supported by both ends.  But software *is* allowed to set an
> upper limit (the Target Link Speed in Link Control 2).  If we initiate
> a retrain and the link doesn't come back up, I wonder if we should try
> to help the hardware out by using Target Link Speed to limit to a
> lower speed and attempting another retrain, something like this hacky
> patch: (please collect the dmesg log if you try this)

Well, I tried it, but don't see any of the 'lnkcap2' output from that
new function:

[    1.545853] mvebu-pcie soc:pcie: host bridge /soc/pcie ranges:
[    1.545878] mvebu-pcie soc:pcie:      MEM 0x00f1080000..0x00f1081fff -> 0x0000080000
[    1.545894] mvebu-pcie soc:pcie:      MEM 0x00f1040000..0x00f1041fff -> 0x0000040000
[    1.545907] mvebu-pcie soc:pcie:      MEM 0x00f1044000..0x00f1045fff -> 0x0000044000
[    1.545920] mvebu-pcie soc:pcie:      MEM 0x00f1048000..0x00f1049fff -> 0x0000048000
[    1.545933] mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0100000000
[    1.545945] mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0100000000
[    1.545958] mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0200000000
[    1.545970] mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0200000000
[    1.545982] mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0300000000
[    1.545994] mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0300000000
[    1.546006] mvebu-pcie soc:pcie:      MEM 0xffffffffffffffff..0x00fffffffe -> 0x0400000000
[    1.546014] mvebu-pcie soc:pcie:       IO 0xffffffffffffffff..0x00fffffffe -> 0x0400000000
[    1.546181] mvebu-pcie soc:pcie: PCI host bridge to bus 0000:00
[    1.546190] pci_bus 0000:00: root bus resource [bus 00-ff]
[    1.546197] pci_bus 0000:00: root bus resource [mem 0xf1080000-0xf1081fff] (bus address [0x00080000-0x00081fff])
[    1.546204] pci_bus 0000:00: root bus resource [mem 0xf1040000-0xf1041fff] (bus address [0x00040000-0x00041fff])
[    1.546210] pci_bus 0000:00: root bus resource [mem 0xf1044000-0xf1045fff] (bus address [0x00044000-0x00045fff])
[    1.546216] pci_bus 0000:00: root bus resource [mem 0xf1048000-0xf1049fff] (bus address [0x00048000-0x00049fff])
[    1.546220] pci_bus 0000:00: root bus resource [mem 0xe0000000-0xe7ffffff]
[    1.546225] pci_bus 0000:00: root bus resource [io  0x1000-0xeffff]
[    1.546294] pci 0000:00:01.0: [11ab:6820] type 01 class 0x060400
[    1.546308] pci 0000:00:01.0: reg 0x38: [mem 0x00000000-0x000007ff pref]
[    1.546482] pci 0000:00:02.0: [11ab:6820] type 01 class 0x060400
[    1.546495] pci 0000:00:02.0: reg 0x38: [mem 0x00000000-0x000007ff pref]
[    1.546643] pci 0000:00:03.0: [11ab:6820] type 01 class 0x060400
[    1.546656] pci 0000:00:03.0: reg 0x38: [mem 0x00000000-0x000007ff pref]
[    1.547379] PCI: bus0: Fast back to back transfers disabled
[    1.547387] pci 0000:00:01.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[    1.547394] pci 0000:00:02.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[    1.547402] pci 0000:00:03.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[    1.547484] pci 0000:01:00.0: [168c:002e] type 00 class 0x028000
[    1.547507] pci 0000:01:00.0: reg 0x10: [mem 0xe8000000-0xe800ffff 64bit]
[    1.547615] pci 0000:01:00.0: supports D1
[    1.547620] pci 0000:01:00.0: PME# supported from D0 D1 D3hot
[    1.547730] pci 0000:00:01.0: ASPM: current common clock configuration is inconsistent, reconfiguring
[    1.631937] PCI: bus2: Fast back to back transfers enabled
[    1.631945] pci_bus 0000:02: busn_res: [bus 02-ff] end is updated to 02
[    1.632655] PCI: bus3: Fast back to back transfers enabled
[    1.632662] pci_bus 0000:03: busn_res: [bus 03-ff] end is updated to 03
[    1.632694] pci 0000:00:01.0: BAR 8: assigned [mem 0xe0000000-0xe00fffff]
[    1.632702] pci 0000:00:02.0: BAR 8: assigned [mem 0xe0200000-0xe04fffff]
[    1.632710] pci 0000:00:01.0: BAR 6: assigned [mem 0xe0100000-0xe01007ff pref]
[    1.632718] pci 0000:00:02.0: BAR 6: assigned [mem 0xe0500000-0xe05007ff pref]
[    1.632726] pci 0000:00:03.0: BAR 6: assigned [mem 0xe0600000-0xe06007ff pref]
[    1.632734] pci 0000:01:00.0: BAR 0: assigned [mem 0xe0000000-0xe000ffff 64bit]
[    1.632741] pci 0000:01:00.0: BAR 0: error updating (0xe0000004 != 0xffffffff)
[    1.632746] pci 0000:01:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
[    1.632752] pci 0000:00:01.0: PCI bridge to [bus 01]
[    1.632760] pci 0000:00:01.0:   bridge window [mem 0xe0000000-0xe00fffff]
[    1.632769] pci 0000:02:00.0: BAR 0: assigned [mem 0xe0200000-0xe03fffff 64bit]
[    1.632776] pci 0000:02:00.0: BAR 0: error updating (0xe0200004 != 0xffffffff)
[    1.632782] pci 0000:02:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
[    1.632788] pci 0000:02:00.0: BAR 6: assigned [mem 0xe0400000-0xe040ffff pref]
[    1.632793] pci 0000:00:02.0: PCI bridge to [bus 02]
[    1.632800] pci 0000:00:02.0:   bridge window [mem 0xe0200000-0xe04fffff]
[    1.632807] pci 0000:00:03.0: PCI bridge to [bus 03]

(and then later, still):
[    3.476364] pci 0000:00:01.0: enabling device (0140 -> 0142)
[    3.477542] ata1: SATA link down (SStatus 0 SControl 300)
[    3.482126] ath9k 0000:01:00.0: enabling device (0000 -> 0002)
[    3.487487] ata2: SATA link down (SStatus 0 SControl 300)
[    3.493379] ath: phy0: Mac Chip Rev 0xfffc0.f is not supported by this driver
[    3.505891] ath: phy0: Unable to initialize hardware; initialization status: -95
[    3.513325] ath9k 0000:01:00.0: Failed to initialize device
[    3.518933] ath9k: probe of 0000:01:00.0 failed with error -95
[    3.524862] ath10k_pci 0000:02:00.0: of_irq_parse_pci: failed with rc=134
[    3.531904] pci 0000:00:02.0: enabling device (0140 -> 0142)
[    3.537590] ath10k_pci 0000:02:00.0: can't change power state from D3hot to D0 (config space inaccessible)
[    3.577436] ath10k_pci 0000:02:00.0: failed to wake up device : -110
[    3.583948] ath10k_pci: probe of 0000:02:00.0 failed with error -110


-Toke