Re: [PATCH 1/2] drm: introduce page_flip_timeout()

["Christian König" <christian.koenig@amd.com>]

On 1/27/26 23:57, Alex Deucher wrote:
> On Tue, Jan 27, 2026 at 5:53 PM Hamza Mahfooz
> <someguy@effective-light.com> wrote:
>>
>> On Mon, Jan 26, 2026 at 09:20:55AM -0500, Alex Deucher wrote:
>>> I suspect just calling drm_crtc_send_vblank_event() here on the
>>> relevant crtcs would be enough.
>>>
>>
>> Seems like an interesting idea, though I would imagine we would still
>> want to attempt a reset (of some kind) assuming that the subsequent page
>> flip also experiences a timeout.
> 
> Is it actually a timeout or just missed interrupts?  I'm wondering if
> some power feature races with the modeset and causes the interrupt to
> get missed from time to time.

That is my strong suspicion as well.

Even if we missed a vblank interrupt that thing is reoccurring, so the worst thing that can happen is that we delayed reporting back success by one frame.

So something must have turned the CRTC fully off.

BTW: suspending the DAL or event resetting the GPU in such a callback are just hacks, don't be surprised if you run into things like NULL pointer dereferences etc....

Christian.

> 
> Alex