diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 36df7df5fe1a..6fac4129e6a2 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1082,10 +1082,12 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 		lct = drm_dp_calculate_rad(port, rad);
 
 		port->mstb = drm_dp_add_mst_branch_device(lct, rad);
-		port->mstb->mgr = port->mgr;
-		port->mstb->port_parent = port;
+		if (port->mstb) {
+			port->mstb->mgr = port->mgr;
+			port->mstb->port_parent = port;
 
-		send_link = true;
+			send_link = true;
+		}
 		break;
 	}
 	return send_link;