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

From: Christian König

Date: Wed Jan 28 2026 - 09:40:07 EST


On 1/28/26 15:25, Michel Dänzer wrote:
> On 1/28/26 12:25, Christian König wrote:
>> On 1/28/26 10:19, Timur Kristóf wrote:
>>> On 2026. január 26., hétfő 14:00:59 közép-európai téli idő Christian König
>>> wrote:
>>>> On 1/26/26 11:27, Michel Dänzer wrote:
>>>>> On 1/26/26 11:14, Christian König wrote:
>>>>>>
>>>>>> But looking at the slide Harry actually pointed out what immediately came
>>>>>> to my mind as well, e.g. that the Compositor needs to issue a full
>>>>>> modeset to re-program the CRTC.>
>>>>> In principle, the kernel driver has all the information it needs to
>>>>> reprogram the HW by itself. Not sure why the compositor would need to be
>>>>> actively involved.
>>>>
>>>> [...]
>>>>
>>>> Then second even if the kernel can do it I'm not sure if it should do it.
>>>>
>>>> [...]
>>>
>>> I agree with Michel here. It's a kernel bug, it should be solved by the
>>> kernel. I don't like the tendency of pushing userspace to handle kernel bugs,
>>> especially if this is just needed for one vendor's buggy driver. (No offence.)
>>
>> Well I strongly disagree. The kernel is not here to serve userspace, [...]
>
> Can't say I agree with that statement.
>
> Anyway, user space certainly isn't here to kick the kernel back into gear after it hit a bug, or to tell it things it already knows.

That is a really good argument. But the kernel should also not hide that something went wrong from userspace. E.g. flaky HDP pins for example.

Regards,
Christian.

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