diff --git a/[refs] b/[refs]
index 8bd10d918b4f..c26fec1d7f2e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5ddbb26b8b571231cace9f013b2d0ae66229b316
+refs/heads/master: 81ae1b3c31a91358950011fee16698226a1bda45
diff --git a/trunk/drivers/usb/serial/quatech2.c b/trunk/drivers/usb/serial/quatech2.c
index 085cad471c41..3c278521f7e2 100644
--- a/trunk/drivers/usb/serial/quatech2.c
+++ b/trunk/drivers/usb/serial/quatech2.c
@@ -422,12 +422,6 @@ static void qt2_close(struct usb_serial_port *port)
 	port_priv->urb_in_use = false;
 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
 
-	mutex_lock(&port->serial->disc_mutex);
-	if (port->serial->disconnected) {
-		mutex_unlock(&port->serial->disc_mutex);
-		return;
-	}
-
 	/* flush the port transmit buffer */
 	i = usb_control_msg(serial->dev,
 			    usb_rcvctrlpipe(serial->dev, 0),
@@ -458,8 +452,6 @@ static void qt2_close(struct usb_serial_port *port)
 	if (i < 0)
 		dev_err(&port->dev, "%s - close port failed %i\n",
 			__func__, i);
-
-	mutex_unlock(&port->serial->disc_mutex);
 }
 
 static void qt2_disconnect(struct usb_serial *serial)