Re: 5.2-rc1 on droid4: spi crash

[Tony Lindgren <tony@atomide.com>]

Hi,

* Sebastian Reichel <sre@kernel.org> [190523 09:33]:
> Hi,
> 
> On Thu, May 23, 2019 at 11:09:26AM +0200, Pavel Machek wrote:
> > This was greeting me overnight... I don't yet know how reproducible it
> > is, it happened once so far.
> 
> Please pipe the stacktrace into ./scripts/decode_stacktrace.sh
> to get a readable stacktrace, otherwise this is pretty much useless.
> FWIW the only SPI device in the Droid 4 is the PMIC.

I've seen this too, and looks like reverting commit c9ba7a16d0f1
("spi: Release spi_res after finalizing message") fixes it based
several days of testing.

Noralf and Mark, any ideas what needs to be fixed here?

Below is the stacktrace I see without c9ba7a16d0f1 reverted,
not sure how to reproduce but it seems to happen within about
one to two days of uptime.

Regards,

Tony

8< -----------------
Unable to handle kernel NULL pointer dereference at virtual address 00000008
pgd = 829f0a5b
[00000008] *pgd=00000000
Internal error: Oops: 80000005 [#1] SMP ARM
...
CPU: 0 PID: 71 Comm: spi0 Tainted: G        W         5.2.0-rc1+ #5983
Hardware name: Generic OMAP4 (Flattened Device Tree)
PC is at 0x8
LR is at spi_res_release+0x54/0x80
pc : [<00000008>]    lr : [<c06faa48>]    psr: 20000113
sp : ed6e3e88  ip : ed6e3eb0  fp : ed6e3eac
r10: c0b9eca8  r9 : 00000100  r8 : 00000200
r7 : ed65bc00  r6 : ed6e5d3c  r5 : ed6e5d0c  r4 : c0d05254
r3 : 00000008  r2 : c0d05264  r1 : ed6e5d0c  r0 : ed65bc00
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: abf3c04a  DAC: 00000051
Process spi0 (pid: 71, stack limit = 0x0ef66f65)
Stack: (0xed6e3e88 to 0xed6e4000)
3e80:                   ed6e5cd0 ed6e5d0c ed65bc00 c0daf080 00000000 ed510410
3ea0: ed6e3eec ed6e3eb0 c06fd8c4 c06faa00 ed65b800 00000000 ed65ba20 ed65bee0
3ec0: ed6e3eec ed65bc00 ed6e5cd0 ed6e5d0c 00000000 ed510410 ed510410 00000001
3ee0: ed6e3f2c ed6e3ef0 c06fdcd4 c06fd560 00000004 c0170948 ed6e3f20 ed65bdfc
3f00: ffffe000 ed65be68 ed65be44 ffffe000 c0dc7734 ed65be48 c0166f88 00000000
3f20: ed6e3f3c ed6e3f30 c06fe10c c06fd9a4 ed6e3f74 ed6e3f40 c0166f54 c06fe0f8
3f40: ed6e3f74 6eb8f9ff c0166780 00000000 ed3bccc0 ed659c00 ed6e2000 ed65be44
3f60: c0166eac ed115c44 ed6e3fac ed6e3f78 c0166e58 c0166eb8 ed3bccdc ed3bccdc
3f80: ed6e3fac ed659c00 c0166cf8 00000000 00000000 00000000 00000000 00000000
3fa0: 00000000 ed6e3fb0 c01010e8 c0166d04 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
Backtrace:
[<c06fa9f4>] (spi_res_release) from [<c06fd8c4>] (spi_transfer_one_message+0x370/0x444)
 r9:ed510410 r8:00000000 r7:c0daf080 r6:ed65bc00 r5:ed6e5d0c r4:ed6e5cd0
[<c06fd554>] (spi_transfer_one_message) from [<c06fdcd4>] (__spi_pump_messages+0x33c/0x754)
 r10:00000001 r9:ed510410 r8:ed510410 r7:00000000 r6:ed6e5d0c r5:ed6e5cd0
 r4:ed65bc00
[<c06fd998>] (__spi_pump_messages) from [<c06fe10c>] (spi_pump_messages+0x20/0x24)
 r10:00000000 r9:c0166f88 r8:ed65be48 r7:c0dc7734 r6:ffffe000 r5:ed65be44
 r4:ed65be68
[<c06fe0ec>] (spi_pump_messages) from [<c0166f54>] (kthread_worker_fn+0xa8/0x268)
[<c0166eac>] (kthread_worker_fn) from [<c0166e58>] (kthread+0x160/0x178)
 r10:ed115c44 r9:c0166eac r8:ed65be44 r7:ed6e2000 r6:ed659c00 r5:ed3bccc0
 r4:00000000
[<c0166cf8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
Exception stack(0xed6e3fb0 to 0xed6e3ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0166cf8
 r4:ed659c00
Code: bad PC value
---[ end trace a8011e9722dfda5e ]---