usb: dwc3: drd: Defer probe if extcon device is not found

In case the "linux,extcon-name" property is defined but device itself
is not ready, defer the probe.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/drd.c

@@ -457,8 +457,13 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 	 * This device property is for kernel internal use only and
 	 * is expected to be set by the glue code.
 	 */
-	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0)
-		return extcon_get_extcon_dev(name);
+	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0) {
+		edev = extcon_get_extcon_dev(name);
+		if (!edev)
+			return ERR_PTR(-EPROBE_DEFER);
+
+		return edev;
+	}
 
 	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
 	np_conn = of_graph_get_remote_node(np_phy, -1, -1);