drm/bridge: ti-sn65dsi86: support DRM_BRIDGE_ATTACH_NO_CONNECTOR

Now as the driver does not depend on pdata->connector, add support for
attaching the bridge with DRM_BRIDGE_ATTACH_NO_CONNECTOR.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220711092117.360797-3-dmitry.baryshkov@linaro.org

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -698,11 +698,6 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge,
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 	int ret;
 
-	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
-		DRM_ERROR("Fix bridge driver to make connector optional!");
-		return -EINVAL;
-	}
-
 	pdata->aux.drm_dev = bridge->dev;
 	ret = drm_dp_aux_register(&pdata->aux);
 	if (ret < 0) {
@@ -710,15 +705,18 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge,
 		return ret;
 	}
 
-	/* We never want the next bridge to *also* create a connector: */
-	flags |= DRM_BRIDGE_ATTACH_NO_CONNECTOR;
-
-	/* Attach the next bridge */
+	/*
+	 * Attach the next bridge.
+	 * We never want the next bridge to *also* create a connector.
+	 */
 	ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
-				&pdata->bridge, flags);
+				&pdata->bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret < 0)
 		goto err_initted_aux;
 
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+		return 0;
+
 	pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
 						     pdata->bridge.encoder);
 	if (IS_ERR(pdata->connector)) {