Re: PCI: imx6: crash when using Thumb2

[Lucas Stach <l.stach@pengutronix.de>]

Hi Stefan,

Am Montag, den 26.11.2018, 17:16 +0100 schrieb Stefan Agner:
> Hi,
> 
> During debugging of the DBI register length limitation I encountered
> another issue which only seem to appear when building a Thumb2
> kernel.
> I added a print in dw_pcie_read and compared all reads between Thumb2
> and ARM, the two kernel seem to read exactly the same offsets. The
> only difference is that the Thumb2 kernel crashes when reading that
> particular register...

What's connected to this PCIe port? If there is a bridge involved, then
some aborts are expected while scanning the downstream ports for
connected devices. Normally this is handled by the fault handler
installed by the driver, but I'm not sure if this has seen much testing
with a Thumb kernel. So could well be that the fault handler isn't
correctly adjusting the PC or something like that when the kernel is in
Thumb mode.

Regards,
Lucas

> Booting Linux on physical CPU 0x0
> Linux version 4.19.4-00044-ged7a0cc2ef01-dirty (ags@trochilidae) (gcc
> version 7.2.1 20171011 (Linaro GCC 7.2-2017.11)) #459 SMP PREEMPT Mon
> Nov 26 16:28:46 CET 2018
> CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=50c5387d
> CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction
> cache
> OF: fdt: Machine model: Toradex Apalis iMX6Q/D Module on Apalis
> Evaluation Board
> earlycon: ec_imx21 at MMIO 0x02020000 (options '115200n8')
> bootconsole [ec_imx21] enabled
> Memory policy: Data cache writealloc
> cma: Reserved 64 MiB at 0x4c000000
> random: get_random_bytes called from start_kernel+0x85/0x338 with
> crng_init=0
> percpu: Embedded 16 pages/cpu @(ptrval) s36108 r8192 d21236 u65536
> Built 1 zonelists, mobility grouping on.  Total pages: 260608
> Kernel command line: root=LABEL=otaroot rootfstype=ext4 earlycon
> video=LVDS-1:e hw_random.default_quality=100 console=tty1
> console=ttymxc0,115200
> ostree=/ostree/boot.1/torizon/43498cf0ceac1b957d061dfefdf6268380a412e
> ac513fac22177b8b4a523f35b/0
> Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
> Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
> Memory: 957960K/1048576K available (7168K kernel code, 421K rwdata,
> 3388K rodata, 1024K init, 419K bss, 25080K reserved, 65536K cma-
> reserved, 196608K highmem)
> Virtual kernel memory layout:
>     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
>     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
>     vmalloc : 0xf0800000 - 0xff800000   ( 240 MB)
>     lowmem  : 0xc0000000 - 0xf0000000   ( 768 MB)
>     pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
>     modules : 0xbf800000 - 0xbfe00000   (   6 MB)
>       .text : 0x(ptrval) - 0x(ptrval)   (8160 kB)
>       .init : 0x(ptrval) - 0x(ptrval)   (1024 kB)
>       .data : 0x(ptrval) - 0x(ptrval)   ( 422 kB)
>        .bss : 0x(ptrval) - 0x(ptrval)   ( 420 kB)
> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
> rcu: Preemptible hierarchical RCU implementation.
>  Tasks RCU enabled.
> NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
> L2C-310 errata 752271 769419 enabled
> L2C-310 enabling early BRESP for Cortex-A9
> L2C-310 full line of zeros enabled for Cortex-A9
> L2C-310 ID prefetch enabled, offset 16 lines
> L2C-310 dynamic clock gating enabled, standby mode enabled
> L2C-310 cache controller enabled, 16 ways, 1024 kB
> L2C-310: CACHE_ID 0x410000c7, AUX_CTRL 0x76470001
> Switching to timer-based delay loop, resolution 333ns
> sched_clock: 32 bits at 3000kHz, resolution 333ns, wraps every
> 715827882841ns
> clocksource: mxc_timer1: mask: 0xffffffff max_cycles: 0xffffffff,
> max_idle_ns: 637086815595 ns
> Console: colour dummy device 80x30
> console [tty1] enabled
> Calibrating delay loop (skipped), value calculated using timer
> frequency.. 6.00 BogoMIPS (lpj=30000)
> pid_max: default: 32768 minimum: 301
> Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
> Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
> CPU: Testing write buffer coherency: ok
> CPU0: Spectre v2: using BPIALL workaround
> CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
> Setting up static identity map for 0x10100000 - 0x10100054
> rcu: Hierarchical SRCU implementation.
> smp: Bringing up secondary CPUs ...
> CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
> CPU1: Spectre v2: using BPIALL workaround
> CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
> CPU2: Spectre v2: using BPIALL workaround
> CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
> CPU3: Spectre v2: using BPIALL workaround
> smp: Brought up 1 node, 4 CPUs
> SMP: Total of 4 processors activated (24.00 BogoMIPS).
> CPU: All CPU(s) started in SVC mode.
> devtmpfs: initialized
> VFP support v0.3: implementor 41 architecture 3 part 30 variant 9 rev
> 4
> clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff,
> max_idle_ns: 19112604462750000 ns
> futex hash table entries: 1024 (order: 4, 65536 bytes)
> pinctrl core: initialized pinctrl subsystem
> NET: Registered protocol family 16
> DMA: preallocated 256 KiB pool for atomic coherent allocations
> cpuidle: using governor menu
> CPU identified as i.MX6Q, silicon rev 1.5
> vdd1p1: supplied by regulator-dummy
> vdd3p0: supplied by regulator-dummy
> vdd2p5: supplied by regulator-dummy
> vddarm: supplied by regulator-dummy
> vddpu: supplied by regulator-dummy
> vddsoc: supplied by regulator-dummy
> No ATAGs?
> hw-breakpoint: found 5 (+1 reserved) breakpoint and 1 watchpoint
> registers.
> hw-breakpoint: maximum watchpoint size is 4 bytes.
> imx6q-pinctrl 20e0000.iomuxc: initialized IMX pinctrl driver
> Serial: AMBA PL011 UART driver
> mxs-dma 110000.dma-apbh: initialized
> usb_host_vbus: supplied by usb_host_vbus_hub
> vgaarb: loaded
> SCSI subsystem initialized
> usbcore: registered new interface driver usbfs
> usbcore: registered new interface driver hub
> usbcore: registered new device driver usb
> i2c i2c-0: IMX I2C adapter registered
> i2c i2c-0: can't use DMA, using PIO instead.
> stmpe-i2c 2-0041: stmpe811 detected, chip id: 0x811
> i2c i2c-2: IMX I2C adapter registered
> i2c i2c-2: can't use DMA, using PIO instead.
> gpio-81 (scl): enforced open drain please flag it properly in DT/ACPI
> DSDT/board file
> i2c i2c-1: IMX I2C adapter registered
> i2c i2c-1: can't use DMA, using PIO instead.
> media: Linux media interface: v0.10
> videodev: Linux video capture interface: v2.00
> pps_core: LinuxPPS API ver. 1 registered
> pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti
> <giometti@linux.it>
> PTP clock support registered
> Advanced Linux Sound Architecture Driver Initialized.
> Bluetooth: Core ver 2.22
> NET: Registered protocol family 31
> Bluetooth: HCI device and connection manager initialized
> Bluetooth: HCI socket layer initialized
> Bluetooth: L2CAP socket layer initialized
> Bluetooth: SCO socket layer initialized
> clocksource: Switched to clocksource mxc_timer1
> VFS: Disk quotas dquot_6.6.0
> VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
> NET: Registered protocol family 2
> tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 6144
> bytes)
> TCP established hash table entries: 8192 (order: 3, 32768 bytes)
> TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
> TCP: Hash tables configured (established 8192 bind 8192)
> UDP hash table entries: 512 (order: 2, 16384 bytes)
> UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
> NET: Registered protocol family 1
> RPC: Registered named UNIX socket transport module.
> RPC: Registered udp transport module.
> RPC: Registered tcp transport module.
> RPC: Registered tcp NFSv4.1 backchannel transport module.
> Trying to unpack rootfs image as initramfs...
> Freeing initrd memory: 2516K
> hw perfevents: no interrupt-affinity property for /pmu, guessing.
> hw perfevents: enabled with armv7_cortex_a9 PMU driver, 7 counters
> available
> Initialise system trusted keyrings
> workingset: timestamp_bits=30 max_order=18 bucket_order=0
> NFS: Registering the id_resolver key type
> Key type id_resolver registered
> Key type id_legacy registered
> jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
> fuse init (API version 7.27)
> Key type asymmetric registered
> Asymmetric key parser 'x509' registered
> bounce: pool size: 64 pages
> io scheduler noop registered
> io scheduler deadline registered
> io scheduler cfq registered (default)
> io scheduler mq-deadline registered
> io scheduler kyber registered
> imx6q-pcie 1ffc000.pcie: Linked as a consumer to regulator.12
> imx6q-pcie 1ffc000.pcie: host bridge /soc/pcie@1ffc000 ranges:
> imx6q-pcie 1ffc000.pcie:    IO 0x01f80000..0x01f8ffff -> 0x00000000
> imx6q-pcie 1ffc000.pcie:   MEM 0x01000000..0x01efffff -> 0x01000000
> dw_pcie_read, addr f09bc710, size 4
> [...]
> dw_pcie_read, addr f09bc72c, size 4
> imx6q-pcie 1ffc000.pcie: Link up
> imx6q-pcie 1ffc000.pcie: Link: Gen2 disabled
> dw_pcie_read, addr f09bc080, size 4
> imx6q-pcie 1ffc000.pcie: Link up, Gen1
> imx6q-pcie 1ffc000.pcie: PCI host bridge to bus 0000:00
> pci_bus 0000:00: root bus resource [bus 00-ff]
> pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
> pci_bus 0000:00: root bus resource [mem 0x01000000-0x01efffff]
> dw_pcie_read, addr f09bc000, size 4
> [...]
> dw_pcie_read, addr f09bc004, size 2
> PCI: bus0: Fast back to back transfers disabled
> dw_pcie_read, addr f09bc018, size 4
> [...]
> dw_pcie_read, addr f09bc082, size 2
> pci 0000:01:00.0: 2.000 Gb/s available PCIe bandwidth, limited by 2.5
> GT/s x1 link at 0000:00:00.0 (capable of 7.876 Gb/s with 8 GT/s x1
> link)
> dw_pcie_read, addr f09bc72c, size 4
> [...]
> dw_pcie_read, addr f09bc908, size 4
> PCI: bus1: Fast back to back transfers disabled
> dw_pcie_read, addr f09bc72c, size 4
> [...]
> dw_pcie_read, addr f09bc908, size 4
> pci 0000:01:00.0: bridge configuration invalid ([bus 00-00]),
> reconfiguring
> dw_pcie_read, addr f09bc72c, size 4
> [...]
> dw_pcie_read, addr f09bc72c, size 4
> dw_pcie_read, addr f09bc908, size 4
> dw_pcie_read, addr f0a80000, size 4
> Unhandled fault: external abort on non-linefetch (0x1008) at
> 0xf0a80000
> pgd = (ptrval)
> [f0a80000] *pgd=3c5b1811, *pte=01f40243, *ppte=01f40013
> Internal error: : 1008 [#1] PREEMPT SMP THUMB2
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.4-00044-ged7a0cc2ef01-
> dirty #459
> Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> PC is at dw_pcie_read+0x36/0x54
> LR is at dw_pcie_read+0x19/0x54
> pc : [<c034ab8e>]    lr : [<c034ab71>]    psr: 600000b3
> sp : ec077b80  ip : 00000020  fp : 00000000
> r10: ec077be0  r9 : ec531c10  r8 : 00000004
> r7 : 00000000  r6 : ec077be0  r5 : 00000004  r4 : f0a80000
> r3 : c0619ba3  r2 : c0619ba3  r1 : 00000002  r0 : 00000000
> Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA Thumb  Segment none
> Control: 50c5387d  Table: 1000404a  DAC: 00000051
> Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
> Stack: (0xec077b80 to 0xec078000)
> 7b80: ec531c28 00000000 f0a80000 c034b3e7 01f40000 00000000 02000000
> 00000000
> 7ba0: 00040000 c0c67cc0 0000000a 00000000 c0dbe52c c0d04d08 c034b2f9
> c0d1b650
> 7bc0: ec077c38 00000000 40000013 00000002 00000000 c03366cb ec077be0
> 00000010
> 7be0: 00000000 c0619ba3 ec077c30 c0d04d08 ec077c38 00000000 0000ea60
> ec5c4400
> 7c00: ec085068 c033898f 00000002 c0322f29 c0336e17 c0d04d08 00000000
> 00000000
> 7c20: ec5c4400 00000000 ec085068 00000002 00000000 c0338e39 c0619ba3
> c0619ba3
> 7c40: 00000001 ec5c4400 00000000 00000000 c0d04d08 c0338ea7 00000002
> ec5c4400
> 7c60: ec085000 00000000 c0a81f0c c0339aaf 00000033 c0336e17 00000000
> c0738cff
> 7c80: 00000002 c0336e17 00ff0201 ec5c4000 ec085000 ec5c4400 00000001
> c0d04d08
> 7ca0: ec085068 00000002 00000000 c03398c9 ec5c4000 ec5c4478 00000000
> 00000000
> 7cc0: 00000000 00000001 c0a46ddc 00000001 00ff0201 c0619ba3 01400000
> ec5c4000
> 7ce0: ec085000 00000001 ec5c4014 00000001 00000001 00000000 00000000
> c0339bc9
> 7d00: 00000001 c011dd81 ec36bc00 00000001 00000001 c0339269 0011cc11
> ec36bc00
> 7d20: ec084800 ec5c4000 00000000 c0d04d08 ec084868 00000001 000000ff
> c033994b
> 7d40: ec36bc00 00000000 00000000 00000000 00000000 00000001 c0a46ddc
> 00000001
> 7d60: 00ff0100 c0619ba3 01470000 ec36bc00 ec36bc14 ec084800 ec36bc14
> 00000000
> 7d80: 00000000 00000000 00000000 c0339b59 00000000 ec531c10 ec5aea40
> 00000001
> 7da0: 00000000 c0619ba3 00000000 ec531e00 00000000 ec5aebc0 ec1aee10
> ec531fb0
> 7dc0: 00000000 ec531fb0 ec531e00 c0339d81 c033a32d ec531c28 00000000
> c034ba41
> 7de0: 00000000 00000000 ef7df370 c0a85048 c0a70710 c0a85020 c0a84e4c
> ec41cc10
> 7e00: ec1aee10 ec531c10 ef7df370 ec1aee00 c0d1b760 00000000 00000000
> c034c2fb
> 7e20: 00000000 00000000 ec1aee10 00000000 c0d1b760 00000000 00000000
> c03e8351
> 7e40: c0dc7414 ec1aee10 c0dc7418 c03e7123 ec1aee10 c0d1b760 ec1aee44
> c0d04d08
> 7e60: 00000000 c0c4a83c c0c5e820 c03e72b9 c0d04d08 c0738cff c08390cc
> ec1aee10
> 7e80: c0d1b760 ec1aee44 c0d04d08 00000000 c0c4a83c c0c5e820 00000000
> c03e73ff
> 7ea0: 00000000 c0d1b760 c03e7391 c03e5e17 00000000 ec007b58 ec191fb4
> c0619ba3
> 7ec0: ec007b6c c0d1b760 ec41cb80 00000000 c0d2eb58 c03e6933 c0a854e4
> c0d1b760
> 7ee0: c0d04d08 c0d1b760 c0d04d08 ffffe000 c0c163fb c03e7995 c0d1b74c
> c0d69780
> 7f00: c0d04d08 c01026d7 c0c004fb 00000100 00000100 c012d500 c0abc94c
> c0c004fb
> 7f20: 00000000 00000006 00000006 c0a4caac 00000000 c0d04d08 c0a564cc
> c0a4cb20
> 7f40: 00000000 efffea7d efffea84 c0619ba3 00000000 c0619ba3 c0d69780
> 00000007
> 7f60: c0d69780 c0c4a834 c0d69780 00000100 c0c4a83c c0c00b59 00000006
> 00000006
> 7f80: 00000000 c0c004fb 00000000 c073429d 00000000 00000000 00000000
> 00000000
> 7fa0: 00000000 c07342a3 00000000 c01010f9 00000000 00000000 00000000
> 00000000
> 7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000
> 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000
> 00000000
> [<c034ab8e>] (dw_pcie_read) from [<c034b3e7>]
> (dw_pcie_rd_conf+0xef/0x120)
> [<c034b3e7>] (dw_pcie_rd_conf) from [<c03366cb>]
> (pci_bus_read_config_dword+0x47/0x70)
> [<c03366cb>] (pci_bus_read_config_dword) from [<c033898f>]
> (pci_bus_generic_read_dev_vendor_id+0x17/0xf4)
> [<c033898f>] (pci_bus_generic_read_dev_vendor_id) from [<c0338e39>]
> (pci_scan_single_device+0x41/0x88)
> [<c0338e39>] (pci_scan_single_device) from [<c0338ea7>]
> (pci_scan_slot+0x27/0x98)
> [<c0338ea7>] (pci_scan_slot) from [<c0339aaf>]
> (pci_scan_child_bus_extend+0x2b/0x1c0)
> [<c0339aaf>] (pci_scan_child_bus_extend) from [<c03398c9>]
> (pci_scan_bridge_extend+0x1ed/0x394)
> [<c03398c9>] (pci_scan_bridge_extend) from [<c0339bc9>]
> (pci_scan_child_bus_extend+0x145/0x1c0)
> [<c0339bc9>] (pci_scan_child_bus_extend) from [<c033994b>]
> (pci_scan_bridge_extend+0x26f/0x394)
> [<c033994b>] (pci_scan_bridge_extend) from [<c0339b59>]
> (pci_scan_child_bus_extend+0xd5/0x1c0)
> [<c0339b59>] (pci_scan_child_bus_extend) from [<c0339d81>]
> (pci_scan_root_bus_bridge+0x39/0x84)
> [<c0339d81>] (pci_scan_root_bus_bridge) from [<c034ba41>]
> (dw_pcie_host_init+0x1e5/0x364)
> [<c034ba41>] (dw_pcie_host_init) from [<c034c2fb>]
> (imx6_pcie_probe+0x22f/0x394)
> [<c034c2fb>] (imx6_pcie_probe) from [<c03e8351>]
> (platform_drv_probe+0x2d/0x60)
> [<c03e8351>] (platform_drv_probe) from [<c03e7123>]
> (really_probe+0x12f/0x1cc)
> [<c03e7123>] (really_probe) from [<c03e72b9>]
> (driver_probe_device+0x3d/0x114)
> [<c03e72b9>] (driver_probe_device) from [<c03e73ff>]
> (__driver_attach+0x6f/0x70)
> [<c03e73ff>] (__driver_attach) from [<c03e5e17>]
> (bus_for_each_dev+0x3b/0x64)
> [<c03e5e17>] (bus_for_each_dev) from [<c03e6933>]
> (bus_add_driver+0xff/0x164)
> [<c03e6933>] (bus_add_driver) from [<c03e7995>]
> (driver_register+0x35/0x9c)
> [<c03e7995>] (driver_register) from [<c01026d7>]
> (do_one_initcall+0x3f/0x128)
> [<c01026d7>] (do_one_initcall) from [<c0c00b59>]
> (kernel_init_freeable+0x115/0x180)
> [<c0c00b59>] (kernel_init_freeable) from [<c07342a3>]
> (kernel_init+0x7/0xd0)
> [<c07342a3>] (kernel_init) from [<c01010f9>]
> (ret_from_fork+0x11/0x38)
> Exception stack(0xec077fb0 to 0xec077ff8)
> 7fa0:                                     00000000 00000000 00000000
> 00000000
> 7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000
> 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> Code: f3bf 8f4f 6033 bd70 (6823) f3bf
> ---[ end trace e82f75a9f4dd9bc8 ]---
> note: swapper/0[1] exited with preempt_count 1
> Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b
> [    5.697939]
> CPU1: stopping
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G      D           4.19.4-
> 00044-ged7a0cc2ef01-dirty #459
> Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> [<c010d4f5>] (unwind_backtrace) from [<c01099fb>]
> (show_stack+0xb/0xc)
> [<c01099fb>] (show_stack) from [<c0726a49>] (dump_stack+0x5d/0x6c)
> [<c0726a49>] (dump_stack) from [<c010c34d>] (handle_IPI+0x149/0x158)
> [<c010c34d>] (handle_IPI) from [<c0322f59>]
> (gic_handle_irq+0x6d/0x70)
> [<c0322f59>] (gic_handle_irq) from [<c0101a65>] (__irq_svc+0x65/0xac)
> Exception stack(0xec0b9f60 to 0xec0b9fa8)
> 9f60: 00000000 00000b10 ef7ad4cc c01145a1 ffffe000 c0d04d30 c0d04d6c
> 00000002
> 9f80: 00000000 c0d04d08 c0c675b0 c0a673b0 c0d04de4 ec0b9fb0 c01072dd
> c01072de
> 9fa0: 40000033 ffffffff
> [<c0101a65>] (__irq_svc) from [<c01072de>] (arch_cpu_idle+0x22/0x24)
> [<c01072de>] (arch_cpu_idle) from [<c01360f7>] (do_idle+0x14b/0x1dc)
> [<c01360f7>] (do_idle) from [<c0136397>]
> (cpu_startup_entry+0x13/0x14)
> [<c0136397>] (cpu_startup_entry) from [<10102491>] (0x10102491)
> CPU2: stopping
> CPU: 2 PID: 0 Comm: swapper/2 Tainted: G      D           4.19.4-
> 00044-ged7a0cc2ef01-dirty #459
> Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> [<c010d4f5>] (unwind_backtrace) from [<c01099fb>]
> (show_stack+0xb/0xc)
> [<c01099fb>] (show_stack) from [<c0726a49>] (dump_stack+0x5d/0x6c)
> [<c0726a49>] (dump_stack) from [<c010c34d>] (handle_IPI+0x149/0x158)
> [<c010c34d>] (handle_IPI) from [<c0322f59>]
> (gic_handle_irq+0x6d/0x70)
> [<c0322f59>] (gic_handle_irq) from [<c0101a65>] (__irq_svc+0x65/0xac)
> Exception stack(0xec0bbf60 to 0xec0bbfa8)
> bf60: 00000000 00000810 ef7bd4cc c01145a1 ffffe000 c0d04d30 c0d04d6c
> 00000004
> bf80: 00000000 c0d04d08 c0c675b0 c0a673b0 c0d04de4 ec0bbfb0 c01072dd
> c01072de
> bfa0: 40000033 ffffffff
> [<c0101a65>] (__irq_svc) from [<c01072de>] (arch_cpu_idle+0x22/0x24)
> [<c01072de>] (arch_cpu_idle) from [<c01360f7>] (do_idle+0x14b/0x1dc)
> [<c01360f7>] (do_idle) from [<c0136397>]
> (cpu_startup_entry+0x13/0x14)
> [<c0136397>] (cpu_startup_entry) from [<10102491>] (0x10102491)
> CPU3: stopping
> CPU: 3 PID: 0 Comm: swapper/3 Tainted: G      D           4.19.4-
> 00044-ged7a0cc2ef01-dirty #459
> Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> [<c010d4f5>] (unwind_backtrace) from [<c01099fb>]
> (show_stack+0xb/0xc)
> [<c01099fb>] (show_stack) from [<c0726a49>] (dump_stack+0x5d/0x6c)
> [<c0726a49>] (dump_stack) from [<c010c34d>] (handle_IPI+0x149/0x158)
> [<c010c34d>] (handle_IPI) from [<c0322f59>]
> (gic_handle_irq+0x6d/0x70)
> [<c0322f59>] (gic_handle_irq) from [<c0101a65>] (__irq_svc+0x65/0xac)
> Exception stack(0xec0bdf60 to 0xec0bdfa8)
> df60: 00000000 00000630 ef7cd4cc c01145a1 ffffe000 c0d04d30 c0d04d6c
> 00000008
> df80: 00000000 c0d04d08 c0c675b0 c0a673b0 c0d04de4 ec0bdfb0 c01072dd
> c01072de
> dfa0: 40000033 ffffffff
> [<c0101a65>] (__irq_svc) from [<c01072de>] (arch_cpu_idle+0x22/0x24)
> [<c01072de>] (arch_cpu_idle) from [<c01360f7>] (do_idle+0x14b/0x1dc)
> [<c01360f7>] (do_idle) from [<c0136397>]
> (cpu_startup_entry+0x13/0x14)
> [<c0136397>] (cpu_startup_entry) from [<10102491>] (0x10102491)
> ---[ end Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b
>  ]---
> 
> The patches I have ontop of 4.19.4 are all unrelated. I also can
> reproduce the issue on a vanilla 4.18 kernel. Not really sure what
> is going on here or how to debug that issue... Anybody else seen
> this?
> 
> --
> Stefan