On 2/20/26 09:42, Michel Dänzer wrote: > On 2/18/26 10:22, Michel Dänzer wrote: >> On 2/18/26 01:45, Hamza Mahfooz wrote: >>> On Mon, Feb 16, 2026 at 10:28:13AM +0100, Michel Dänzer wrote: >>>> On 2/14/26 23:16, Hamza Mahfooz wrote: >>>>> On Sat, Feb 14, 2026 at 03:02:49PM +0100, Michel Dänzer wrote: >>>>> >>>>>> 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. >>>>> >>>>> AFAIK that is what the uevent is already doing (unless I'm mistaken). >>>> >>>> This is about just doing a full modeset, which isn't something user space >>>> can do in response to a wedged event. >>> >>> I was referring to what compositors are doing in response to >>> `drm_kms_helper_hotplug_event()`. Perhaps, the enum constants should be >>> renamed, since the forced modeset is actually sent when the current >>> reset phase is DRM_KMS_RESET_NONE (the phase is updated before sending >>> out the event though). >> >> Ah, you're talking about the drm_kms_helper_hotplug_event call in >> drm_atomic_helper_wait_for_flip_done (I thought "uevent" referred to >> drm_dev_wedged_event in patch 2). >> >> I don't know about other compositors, but I don't think mutter will do a >> modeset in response to a hotplug event if no KMS state changed (because some >> monitors can generate spurious hotplug events). > > FWIW, if it really turns out impossible for the kernel to do a modeset itself > (which I remain unconvinced of), one way to require a modeset from user space > is to set the "link-status" connector property to "Bad".
Having written that down, a reason why the kernel can't just do a modeset itself occurred to me: A modeset might affect other CRTCs than the ones affected by the timed-out commit, which could interact badly with other pending commits affecting those other CRTCs. The "link-status" property seems like the best solution so far. (Note that not all compositors are paying attention to it yet, they'll need to be fixed) -- Earthling Michel Dänzer \ GNOME / Xwayland / Mesa developer https://redhat.com \ Libre software enthusiast
