Hi Michel,
On 8/17/23 12:37, Michel Dänzer wrote:
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.
Xaver tested this hypothesis in a flipping the same fb in a VRR monitor
and it worked as expected, so this shouldn't be a concern.
Thanks,
André
