[PATCH] drm: msm: a6xx: fix gpu failure after system resume

[Akhil P Oommen]

On 7/15/2020 12:12 AM, Rob Clark wrote:
> On Tue, Jul 14, 2020 at 10:10 AM Matthias Kaehlcke <mka at chromium.org> wrote:
>>
>> On Tue, Jul 14, 2020 at 06:55:30PM +0530, Akhil P Oommen wrote:
>>> On targets where GMU is available, GMU takes over the ownership of GX GDSC
>>> during its initialization. So, take a refcount on the GX PD on behalf of
>>> GMU before we initialize it. This makes sure that nobody can collapse the
>>> GX GDSC once GMU owns the GX GDSC. This patch fixes some weird failures
>>> during GPU wake up during system resume.
>>>
>>> Signed-off-by: Akhil P Oommen <akhilpo at codeaurora.org>
>>
>> I went through a few dozen suspend/resume cycles on SC7180 and didn't run
>> into the kernel panic that typically occurs after a few iterations without
>> this patch.
>>
>> Reported-by: Matthias Kaehlcke <mka at chromium.org>
>> Tested-by: Matthias Kaehlcke <mka at chromium.org>
>>
>> On which tree is this patch based on? I had to apply it manually because
>> 'git am' is unhappy when I try to apply it:
>>
>>    error: sha1 information is lacking or useless (drivers/gpu/drm/msm/adreno/a6xx_gmu.c).
>>    error: could not build fake ancestor
>>
>> Both upstream and drm-msm are in my remotes and synced, so I suspect it's
>> some private tree. Please make sure to base patches on the corresponding
>> maintainer tree or upstream, whichs makes life easier for maintainers,
>> testers and reviewers.
> 
> I've run into the same issue frequently :-(
> 
> BR,
> -R
> 
Sorry, I was using msm-next brand as the base, but had the opp-next 
branch merged too inadvertently.

-Akhil