lkml.org 
[lkml]   [2015]   [Aug]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] ARM: keystone: add a work around to handle asynchronous external abort
From
Date
Am Dienstag, den 18.08.2015, 09:13 +0100 schrieb Russell King - ARM
Linux:
> On Mon, Aug 17, 2015 at 08:09:17PM -0700, santosh.shilimkar@oracle.com wrote:
> > 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.
>
> Highly unlikely to make any difference. As the failure happens soo early
> with the patch applied, the kernel hasn't had much of a chance to touch
> the hardware - about the only things are the decompressor and the kernel
> touching the early console. As they seem to be working, it suggests
> that's not the cause.
>
> It seems to be pointing towards something in the boot loader...
>
> Normally, uboot will hook itself into the vectors to report errors, but
> I wonder whether uboot enables asynchronous aborts while it's running.
> Don't forget to make sure that the aborts are disabled again prior to
> calling the kernel.
>
At least one of the Marvell platforms has the same issue with the
bootloader (I think it is some downstream U-Boot) leaving an imprecise
abort hanging around as a nice present for Linux to crash on.

If it turns out to be the same issue the only kernel level workaround
would be to ignore exactly 1 abort after bootup.

Then we still need a solution for the platform and the PCIe driver abort
handler both hooking into the same abort vector, which won't work
currently.

Regards,
Lucas
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |



\
 
 \ /
  Last update: 2015-08-18 11:01    [W:0.159 / U:0.216 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site