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: > >> Why couldn't a full modeset? > > > > As far as I see it the only reasons why we should be timing out is > > either an interrupt went missing (perhaps due to a race condition in > > driver code) or hung hardware. In either case, the interrupt associated > > with the page flip for the current commit is long gone. > > That's a matter of bookkeeping, the interrupt isn't required to keep track of > the commit and complete it.
Oh, if you're talking about sending out a "fake" drm_crtc_send_vblank_event(), I had considered that. Though, drivers that have hardware vblank counters take ownership of the relevant `struct drm_pending_vblank_event` [1] pretty early on. So, there wouldn't be a way to ensure that they send that out and that would mean we never get a chance to force a full modeset. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/drm/drm_crtc.h?h=v6.19#n386 > > > >> 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).
