diff --git a/[refs] b/[refs]
index 93a5540c7351..b5b90a283f9e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1595ab5d7d99bc6c9a5548ab3fb83e278eeae409
+refs/heads/master: add477df674db00377d9a4dc0d9b553ce79bc06d
diff --git a/trunk/drivers/net/usb/hso.c b/trunk/drivers/net/usb/hso.c
index 031d07b105af..94a27f764e6b 100644
--- a/trunk/drivers/net/usb/hso.c
+++ b/trunk/drivers/net/usb/hso.c
@@ -1467,7 +1467,8 @@ static void hso_std_serial_write_bulk_callback(struct urb *urb)
 		return;
 	}
 	hso_put_activity(serial->parent);
-	tty_wakeup(serial->tty);
+	if (serial->tty)
+		tty_wakeup(serial->tty);
 	hso_kick_transmit(serial);
 
 	D1(" ");
@@ -1538,7 +1539,8 @@ static void ctrl_callback(struct urb *urb)
 			clear_bit(HSO_SERIAL_FLAG_RX_SENT, &serial->flags);
 	} else {
 		hso_put_activity(serial->parent);
-		tty_wakeup(serial->tty);
+		if (serial->tty)
+			tty_wakeup(serial->tty);
 		/* response to a write command */
 		hso_kick_transmit(serial);
 	}