diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 426afaa..497e29a 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1123,7 +1123,9 @@
 {
 	struct usb_serial *serial = usb_get_intfdata(intf);
 
-	return serial->type->resume(serial);
+	if (serial->type->resume)
+		return serial->type->resume(serial);
+	return 0;
 }
 EXPORT_SYMBOL(usb_serial_resume);