Re: [PATCH v3 1/2] drm: introduce KMS recovery mechanism

Michel Dänzer
2026-02-14T14:03:04Z

On 2/13/26 20:35, Hamza Mahfooz wrote:
> On Thu, Feb 12, 2026 at 06:18:17PM -0600, Mario Limonciello wrote:
>
>>> @@ -1881,13 +1886,43 @@ void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
>>> continue;
>>> ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ);
>>> - if (ret == 0)
>>> - drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n",
>>> - crtc->base.id, crtc->name);
>>> + if (!ret) {
>>> + switch (dev->reset_phase) {
>>> + case DRM_KMS_RESET_NONE:
>>> + drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n",
>>> + crtc->base.id, crtc->name);
>>> + dev->reset_phase = DRM_KMS_RESET_FORCE_MODESET;
>>> + drm_kms_helper_hotplug_event(dev);
>>> + break;
>>
>> Since you're iterating multiple CRTCs if you manage to recover from one
>> with this call shouldn't you keep iterating the rest?
>
> Most measures that the can be implemented at the kernel level (including
> forcing a full modeset), can't save the the current commit.

Why couldn't a full modeset?

> So, in all likelihood we will just end up waiting an extra 10 seconds per CRTC
> (assuming they haven't completed already, unrelated to the forced
> modeset).

In principle it's possible to do (the equivalent of) a modeset with the current state for all CRTCs, no need to do it separately per CRTC.

--
Earthling Michel Dänzer \ GNOME / Xwayland / Mesa developer
https://redhat.com \ Libre software enthusiast