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To:     Andrey Smirnov <andrew.smirnov@gmail.com>
Cc:     linux-crypto@vger.kernel.org,
        Iuliana Prodan <iuliana.prodan@nxp.com>
From:   Greg Ungerer <gerg@kernel.org>
Subject: Re: [PATCH] crypto: caam - select DMA address size at runtime
Message-ID: <e19cec7b-0721-391f-f43e-437062a7eab3@kernel.org>
Date:   Tue, 10 Mar 2020 16:42:52 +1000
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Hi Andrey,

I am tracking down a caam driver problem, where it is dumping on startup
on a Layerscape 1046 based hardware platform. The dump typically looks
something like this:

------------[ cut here ]------------
kernel BUG at drivers/crypto/caam/jr.c:218!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-ac0 #1
Hardware name: Digi AnywhereUSB-8 (DT)
pstate: 40000005 (nZcv daif -PAN -UAO)
pc : caam_jr_dequeue+0x3f8/0x420
lr : tasklet_action_common.isra.17+0x144/0x180
sp : ffffffc010003df0
x29: ffffffc010003df0 x28: 0000000000000001
x27: 0000000000000000 x26: 0000000000000000
x25: ffffff8020aeba80 x24: 0000000000000000
x23: 0000000000000000 x22: ffffffc010ab4e51
x21: 0000000000000001 x20: ffffffc010ab4000
x19: ffffff8020a2ec10 x18: 0000000000000004
x17: 0000000000000001 x16: 6800f1f100000000
x15: ffffffc010de5000 x14: 0000000000000000
x13: ffffffc010de5000 x12: ffffffc010de5000
x11: 0000000000000000 x10: ffffff8073018080
x9 : 0000000000000028 x8 : 0000000000000000
x7 : 0000000000000000 x6 : ffffffc010a11140
x5 : ffffffc06b070000 x4 : 0000000000000008
x3 : ffffff8073018080 x2 : 0000000000000000
x1 : 0000000000000001 x0 : 0000000000000000

Call trace:
  caam_jr_dequeue+0x3f8/0x420
  tasklet_action_common.isra.17+0x144/0x180
  tasklet_action+0x24/0x30
  _stext+0x114/0x228
  irq_exit+0x64/0x70
  __handle_domain_irq+0x64/0xb8
  gic_handle_irq+0x50/0xa0
  el1_irq+0xb8/0x140
  arch_cpu_idle+0x10/0x18
  do_idle+0xf0/0x118
  cpu_startup_entry+0x24/0x60
  rest_init+0xb0/0xbc
  arch_call_rest_init+0xc/0x14
  start_kernel+0x3d0/0x3fc
Code: d3607c21 2a020002 aa010041 17ffff4d (d4210000)
---[ end trace ce2c4c37d2c89a99 ]---


Git bisecting this lead me to commit a1cf573ee95d ("crypto: caam -
select DMA address size at runtime") as the culprit.

I came across commit by Iuliana, 7278fa25aa0e ("crypto: caam -
do not reset pointer size from MCFGR register"). However that
doesn't fix this dumping problem for me (it does seem to occur
less often though). [NOTE: dump above generated with this
change applied].

I initially hit this dump on a linux-5.4, and it also occurs on
linux-5.5 for me.

Any thoughts?

Regards
Greg