Re: [PATCH] ARM: keystone: add a work around to handle asynchronous external abort

From: santosh.shilimkar@xxxxxxxxxx
Date: Mon Aug 17 2015 - 23:10:43 EST


Murali,

On 8/17/15 3:12 PM, Murali Karicheri wrote:
On 08/14/2015 05:56 PM, Russell King - ARM Linux wrote:
On Fri, Aug 14, 2015 at 05:53:00PM -0400, Murali Karicheri wrote:
We have spend some time already to debug the root cause. Do you have
idea on
how this was hunted down on OMAP that we can learn from? The bad
address is
NULL and it seems to happen very rarely and is not easily reproducible.
Don't want to put this workaround, but we couldn't track it down
either. So
any help to debug this will be appreciated.

If you try applying Lucas' patch, you should receive the abort earlier
in the kernel boot up, which may help narrow down what is provoking it.


Unfortunately, this patch causes boot to stop very early just after
local_abt_enable() is called in early_trap_init(). Before and After
applying the patch, here is what the boot log looks like. Do you see any
issue with the patch diff shown below? Patch is applied on top of
v4.2-rc7. I have some additional base port patches applied to boot
kernel on my EVM based on a new SoC.


From the logs this seems to be mostly clock related issue for some
peripheral. If the bootloader clock enable all hack still exists,
may be you can try that out.

Another way to debug this is to start disabling peripheral drivers
from the kernel 1 by 1 and see if the issue goes away.

Regards,
Santosh
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