Re: ✗ i915.CI.Full: failure for drm/i915/display: stop using the configurable fence timeout (rev2)

Jani Nikula
2026-04-08T16:10:27Z

On Wed, 08 Apr 2026, Maarten Lankhorst <maarten.lankhorst@intel.com> wrote:
> Hey,
>
> Den 2026-04-08 kl. 17:14, skrev Jani Nikula:
>> On Thu, 02 Apr 2026, Maarten Lankhorst <maarten.lankhorst@intel.com> wrote:
>>> Den 2026-04-02 kl. 11:40, skrev Jani Nikula:
>>>> On Wed, 03 Dec 2025, Maarten Lankhorst <maarten.lankhorst@intel.com> wrote:
>>>>> Hey,
>>>>>
>>>>> Den 2025-11-25 kl. 18:24, skrev Ville Syrjälä:
>>>>>> On Tue, Nov 25, 2025 at 03:55:02PM +0200, Jani Nikula wrote:
>>>>>>> Maarten, Ville, any ideas what to do about these?
>>>>>> Looks like we need the timeout to unbreak the modeset vs. reset
>>>>>> deadlock in a timely fashion.
>>>>>>
>>>>>> I'm not where we signal/error the fences the modeset is waiting
>>>>>> for, but I guess that must be happening after the whole reset
>>>>>> sequence is done. Doing that earlier would seem like another
>>>>>> solution, but dunno what other fallout it would have.
>>>>> intel_prepare_plane_fb() adds all dma-resv fences for old_obj on
>>>>> intel_crtc_needs_modeset(), does it change anything if we remove that,
>>>>> at least for the GPU reset commit?
>>>> We dropped the ball here a bit, and I'm a bit clueless as to what to
>>>> do. Except we'll need to unify i915 and xe here somehow.
>>>>
>>>> Alternatives:
>>>>
>>>> - Remove the timeout from i915 (the patch at hand), and fix the fallout
>>>> somehow.
>>>>
>>>> - Add the timeout to xe, and fix the fallout, if any.
>>>>
>>>> - Add the timeout to display parent interface, which is a bit meh.
>>>>
>>>>
>>> The mention in the commit is old_obj needs to be wait for flip_done, I do not believe this
>>> is the case that it was ever used in hardware supported by xe, so for xe the wait can be dropped entirely.
>>>
>>> Is this required for i915 still? In that case you can just eliminate
>>> the wait only for xe.
>> Trouble is, doing things differently basically means using the parent
>> interface no matter what.
>>
> The specific wait mentioned in intel_plane_prepare_plane_fb is only
> used in pre-universal plane overlay support, and in xf86-video-intel
> driver on < gen9. (source:
> intel_skylake_info specifies gen = 0110,
> and sna_wait_for_scanline() returns false for gen >= 0110 on sna.)
>
> Adding a < GEN9 check would be sufficient, and not driver specific.

The timeout is still configurable on i915. I'm not sure how to resolve
that part.

BR,
Jani.

--
Jani Nikula, Intel