drm/amd/display: Set flip pending for pipe split

[WHY]
When doing split pipe, if one pipe is pending on flip, the entire
plane's status should be flip pending, otherwise corruption can occur
when OS writes to a surface prematurely.

[HOW]
Clear the flip pending bit before checking pipes, then OR the flip
pending bits from all pipes together to create the flip pending status
of the entire plane.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Eryk Brol <Eryk.Brol@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_surface.c

@@ -119,6 +119,19 @@ const struct dc_plane_status *dc_plane_get_status(
 	if (core_dc->current_state == NULL)
 		return NULL;
 
+	/* Find the current plane state and set its pending bit to false */
+	for (i = 0; i < core_dc->res_pool->pipe_count; i++) {
+		struct pipe_ctx *pipe_ctx =
+				&core_dc->current_state->res_ctx.pipe_ctx[i];
+
+		if (pipe_ctx->plane_state != plane_state)
+			continue;
+
+		pipe_ctx->plane_state->status.is_flip_pending = false;
+
+		break;
+	}
+
 	for (i = 0; i < core_dc->res_pool->pipe_count; i++) {
 		struct pipe_ctx *pipe_ctx =
 				&core_dc->current_state->res_ctx.pipe_ctx[i];

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -2689,7 +2689,7 @@ static void dcn10_update_pending_status(struct pipe_ctx *pipe_ctx)
 	flip_pending = pipe_ctx->plane_res.hubp->funcs->hubp_is_flip_pending(
 					pipe_ctx->plane_res.hubp);
 
-	plane_state->status.is_flip_pending = flip_pending;
+	plane_state->status.is_flip_pending = plane_state->status.is_flip_pending || flip_pending;
 
 	if (!flip_pending)
 		plane_state->status.current_address = plane_state->status.requested_address;