diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c
index 008308780443c83bbaa9f51c5a1856c76d4ff213..9bd6c0697538500485aee1fd70c07d168fe2235b 100644
--- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
+++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
@@ -242,6 +242,9 @@ 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);
 }