diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c
index 66a0e736cc4daa04a7083c46c651d3540dfcdcb5..59cf1d288465a1741a346f12315e717b3aa9487c 100644
--- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
+++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
@@ -241,6 +241,9 @@ radeon_dp_mst_detect(struct drm_connector *connector,
 		to_radeon_connector(connector);
 	struct radeon_connector *master = radeon_connector->mst_port;
 
+	if (drm_connector_is_unregistered(connector))
+		return connector_status_disconnected;
+
 	return drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr,
 				      radeon_connector->port);
 }