Re: [PATCH v6 6/6] drm/doc: Define KMS atomic state set
On 8/15/23 20:57, André Almeida wrote: > From: Pekka Paalanen > > Specify how the atomic state is maintained between userspace and > kernel, plus the special case for async flips. > > Signed-off-by: Pekka Paalanen > Signed-off-by: André Almeida [...] > +An atomic commit with the flag DRM_MODE_PAGE_FLIP_ASYNC is allowed to > +effectively change only the FB_ID property on any planes. No-operation > changes > +are ignored as always. [...] During the hackfest in Brno, it was mentioned that a commit which re-sets the same FB_ID could actually have an effect with VRR: It could trigger scanout of the next frame before vertical blank has reached its maximum duration. Some kind of mechanism is required for this in order to allow user space to perform low frame rate compensation. -- Earthling Michel Dänzer| https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
Re: [PATCH v6 6/6] drm/doc: Define KMS atomic state set
On 8/17/23 12:37, Michel Dänzer wrote: > On 8/15/23 20:57, André Almeida wrote: >> From: Pekka Paalanen >> >> Specify how the atomic state is maintained between userspace and >> kernel, plus the special case for async flips. >> >> Signed-off-by: Pekka Paalanen >> Signed-off-by: André Almeida > > [...] > >> +An atomic commit with the flag DRM_MODE_PAGE_FLIP_ASYNC is allowed to >> +effectively change only the FB_ID property on any planes. No-operation >> changes >> +are ignored as always. [...] > > During the hackfest in Brno, it was mentioned that a commit which re-sets the > same FB_ID could actually have an effect with VRR: It could trigger scanout > of the next frame before vertical blank has reached its maximum duration. > Some kind of mechanism is required for this in order to allow user space to > perform low frame rate compensation. That said, it doesn't make too much sense to use DRM_MODE_PAGE_FLIP_ASYNC for this, since it won't have any effect outside of vertical blank anyway. -- Earthling Michel Dänzer| https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
Wayland governance meeting - 22-25 August
Hello there! Apologies again for the duplicated governance meeting last week. Here's the doodle [1] for next week's meeting about the direct input access protocol [2]. The poll will close and the date for the meeting will be announced on monday the 21st. The meeting will be held on KDE's platform here [3]. Everybody is free to join to listen if they want to, anonymously or not. The notes for this meeting, along with the ones from the previous meetings can be found on the wayland-protocols wiki page [4]. Cheers, Simon [1]: https://nuudel.digitalcourage.de/FM7RK4ZeZGoEIJXf [2]: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/110 [3]: https://meet.kde.org/b/dav-v5j-p0q-6iz [4]: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/wikis/meetings
