drm/amd/display: Avoid updating surface with the same surface under MPO

[ Upstream commit 1a38ded ]

[Why & How]
Although it's dummy updates of surface update for committing stream
updates, we should not have dummy_updates[j].surface all indicating
to the same surface under multiple surfaces case. Otherwise,
copy_surface_update_to_plane() in update_planes_and_stream_state()
will update to the same surface only.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Wayne Lin

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -8934,7 +8934,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		 */
 		dummy_updates = kzalloc(sizeof(struct dc_surface_update) * MAX_SURFACES, GFP_ATOMIC);
 		for (j = 0; j < status->plane_count; j++)
-			dummy_updates[j].surface = status->plane_states[0];
+			dummy_updates[j].surface = status->plane_states[j];
 
 
 		mutex_lock(&dm->dc_lock);