[PATCH] drm/mediatek: Update the fb property mtk_plane_atomic_async_update

[Enric Balletbo i Serra]

Commit 920fffcc8912 ("drm/mediatek: update cursors by using async atomic
update") added support to async updates of cursors by using the new atomic
interface for that. Unfortunately, introduced two issues. The first one is
that since then, the drm_atomic_helper_async_commit triggers a WARNING due
current fb is not the new fb. The second one, is that we get a black screen
connecting the external display on Elm device and another WARNING due vblank
wait timed out.

Swap the fb in mtk_plane_atomic_async_update to fix both issues.

Fixes: 920fffcc8912 ("drm/mediatek: update cursors by using async atomic update")
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---

 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 914cc7619cd7..7eb10115e72a 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -116,6 +116,7 @@ static void mtk_plane_atomic_async_update(struct drm_plane *plane,
 	plane->state->src_h = new_state->src_h;
 	plane->state->src_w = new_state->src_w;
 	state->pending.async_dirty = true;
+	swap(plane->state->fb, new_state->fb);
 
 	mtk_drm_crtc_async_update(new_state->crtc, plane, new_state);
 }
-- 
2.25.0