On Mon, 16 Oct 2023 12:52:32 +0200There's an effect in the refresh rate, the image won't change but it will report that a flip had happened asynchronously so the reported framerate will be increased. Maybe an additional wording could be like:
André Almeida <andrealmeid@xxxxxxxxxx> wrote:
Hi Michel,Right, so it must have some effect. It cannot be simply ignored like in
On 8/17/23 12:37, Michel Dänzer wrote:
On 8/15/23 20:57, André Almeida wrote:Xaver tested this hypothesis in a flipping the same fb in a VRR monitor
From: Pekka Paalanen <pekka.paalanen@xxxxxxxxxxxxx>[...]
Specify how the atomic state is maintained between userspace and
kernel, plus the special case for async flips.
Signed-off-by: Pekka Paalanen <pekka.paalanen@xxxxxxxxxxxxx>
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
+An atomic commit with the flag DRM_MODE_PAGE_FLIP_ASYNC is allowed toDuring 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.
+effectively change only the FB_ID property on any planes. No-operation changes
+are ignored as always. [...]
and it worked as expected, so this shouldn't be a concern.
the proposed doc wording. Do we special-case re-setting the same FB_ID
as "not a no-op" or "not ignored" or some other way?
Thanks,
pq