drm: bridge: simple-bridge: Make connector creation optional

Make the connector creation optional to enable usage of the
simple-bridge with the DRM bridge connector helper.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200526011505.31884-8-laurent.pinchart+renesas@ideasonboard.com

drivers/gpu/drm/bridge/simple-bridge.c

@@ -105,16 +105,14 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
 	struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
 	int ret;
 
-	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
-		DRM_ERROR("Fix bridge driver to make connector optional!");
-		return -EINVAL;
-	}
-
 	ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret < 0)
 		return ret;
 
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+		return 0;
+
 	if (!bridge->encoder) {
 		DRM_ERROR("Missing encoder\n");
 		return -ENODEV;
@@ -131,8 +129,7 @@ static int simple_bridge_attach(struct drm_bridge *bridge,
 		return ret;
 	}
 
-	drm_connector_attach_encoder(&sbridge->connector,
-					  bridge->encoder);
+	drm_connector_attach_encoder(&sbridge->connector, bridge->encoder);
 
 	return 0;
 }