Re: mainline/master boot bisection: v4.19-12838-g71e56028173b on beagle-xm

[Guillaume Tucker <guillaume.tucker@collabora.com>]

On 06/11/2018 10:54, Guillaume Tucker wrote:
> On 05/11/2018 14:33, Olof Johansson wrote:
>> On Mon, Nov 5, 2018 at 1:43 AM Guillaume Tucker
>> <guillaume.tucker@collabora.com> wrote:
>>>
>>> Hi Linus,
>>>
>>> Please see below, the kernelci.org automated boot bisection found
>>> that the OMAP3 BeagleBoard-xM is failing to boot with SMP
>>> disabled and PREEMPT enabled in multi_v7_defconfig.  There is no
>>> log output after the bootloader so the kernel seems to be
>>> crashing very early on.
>>
>> Can you enable DEBUG_LL to capture what goes wrong?
> 
> Yes I've scheduled a re-run of the automated bisection with
> DEBUG_LL turned on, but the beagle-xm board is currently offline
> in lab-baylibre.  I'll keep you posted when I get some results.

Unfortunately, enabling the DEBUG_LL config didn't help.  There's
still no visible kernel log at all from the failing LAVA jobs:

    http://lava.baylibre.com:10080/scheduler/alljobs?length=25&search=lava-bisect-9638#table


This might be a hard one to debug without physical access to the
board, but please let me know if you think there's anything else
I can try.  For example, if there's a known older kernel revision
where the combination of SMP=n and PREEMPT=y worked then I could
try to run an automated boot bisection based on that.

Guillaume

>> The regression is on me. Linus sent the patch, but I was trigger happy
>> and applied it to fixes instead of letting it soak in -next longer.
>>
>> I'll revert it in our fixes branch and send it in quickly, and apply
>> it to a branch picked up by -next instead.
> 
> Ack - will also keep an eye on boot reports.
> 
> Guillaume
>