drm/atomic: Allow userspace to use explicit sync with atomic async flips

[ Upstream commit e0fa4132bfae725a60c50d53bac80ec31fc20d89 ]

Allow userspace to use explicit synchronization with atomic async flips.
That means that the flip will wait for some hardware fence, and then
will flip as soon as possible (async) in regard of the vblank.

Fixes: 0e26cc72c71c ("drm: Refuse to async flip with atomic prop changes")
Signed-off-by: André Almeida <andrealmeid@igalia.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20240702212215.109696-1-andrealmeid@igalia.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index fc16fddee5c59961aff9220832d1c7b91680ca61..fef4849a4ec219e7259c754ded7b37c5e35e77e2 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1066,7 +1066,9 @@ int drm_atomic_set_property(struct drm_atomic_state *state,
                        break;
                }
 
-               if (async_flip && prop != config->prop_fb_id) {
+               if (async_flip &&
+                   prop != config->prop_fb_id &&
+                   prop != config->prop_in_fence_fd) {
                        ret = drm_atomic_plane_get_property(plane, plane_state,
                                                            prop, &old_val);
                        ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);