[PATCH 1/2] drm/amdgpu: Fix error handling in amdgpu_flip_work_func.

[Alex Deucher]

On Sat, Mar 5, 2016 at 3:00 AM, Michel Dänzer <michel at daenzer.net> wrote:
> On 02.03.2016 05:31, Mario Kleiner wrote:
>> The patch e1d09dc0ccc6: "drm/amdgpu: Don't hang in
>> amdgpu_flip_work_func on disabled crtc." from Feb 19, 2016, leads to
>> the following static checker warning, as reported by Dan Carpenter in
>> https://lists.freedesktop.org/archives/dri-devel/2016-February/101987.html
>>
>> drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:127 amdgpu_flip_work_func()       warn: should this be 'repcnt == -1'
>> drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:136 amdgpu_flip_work_func() error: double unlock 'spin_lock:&crtc->dev->event_lock'
>> drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:136 amdgpu_flip_work_func() error: double unlock 'irqsave:flags'
>>
>> This patch fixes both reported problems:
>>
>> Change post-decrement of repcnt to pre-decrement, so
>> it can't underflow anymore, but still performs up to
>> three repetitions - three is the maximum one could
>> expect in practice.
>>
>> Move the spin_unlock_irqrestore to where it actually
>> belongs.
>>
>> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
>> Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
>> Cc: <stable at vger.kernel.org> # 4.4+
>> Cc: Michel Dänzer <michel.daenzer at amd.com>
>> Cc: Alex Deucher <alexander.deucher at amd.com>
>
> Both patches are
>
> Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>
>
>
> Alex, these should go into 4.5 if at all possible.

Yup, Added to my 4.5 fixes tree.

Alex