drm/bridge: tfp410: Allow operation without drm_connector

The tfp410 driver can operate as part of a pipeline where the
drm_connector is created by the display controller. Enable this mode of
operation by skipping creation of a drm_connector internally.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-20-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/bridge/ti-tfp410.c

@@ -124,10 +124,8 @@ static int tfp410_attach(struct drm_bridge *bridge,
 	if (ret < 0)
 		return ret;
 
-	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
-		DRM_ERROR("Fix bridge driver to make connector optional!");
-		return -EINVAL;
-	}
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+		return 0;
 
 	if (!bridge->encoder) {
 		dev_err(dvi->dev, "Missing encoder\n");