On 8/21/23 22:02, André Almeida wrote: > Em 17/08/2023 07:37, Michel Dänzer escreveu: >> On 8/15/23 20:57, André Almeida wrote: >>> From: Pekka Paalanen <pekka.paala...@collabora.com> >>> >>> Specify how the atomic state is maintained between userspace and >>> kernel, plus the special case for async flips. >>> >>> Signed-off-by: Pekka Paalanen <pekka.paala...@collabora.com> >>> Signed-off-by: André Almeida <andrealm...@igalia.com> >> >> [...] >> >>> +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. >> > > I believe the documentation already addresses that sending redundant > information may not lead to the desired behavior during an async flip. Do you > think adding a note about using the same FB_ID would be helpful?
Maybe not. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
