drm/amd/display: fix pipe re-assignment when odm present

Currently pipe split may steal an existing ODM pipe depending on stream
sequence. This change prevents that from happening as easily.
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Gary Kattan <Gary.Kattan@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -2202,7 +2202,8 @@ static struct pipe_ctx *dcn20_find_secondary_pipe(struct dc *dc,
 		 */
 		if (secondary_pipe == NULL) {
 			for (j = dc->res_pool->pipe_count - 1; j >= 0; j--) {
-				if (dc->current_state->res_ctx.pipe_ctx[j].top_pipe == NULL) {
+				if (dc->current_state->res_ctx.pipe_ctx[j].top_pipe == NULL
+						&& dc->current_state->res_ctx.pipe_ctx[j].prev_odm_pipe == NULL) {
 					preferred_pipe_idx = j;
 
 					if (res_ctx->pipe_ctx[preferred_pipe_idx].stream == NULL) {