diff --git a/[refs] b/[refs]
index 0186e261e582..3f7d41b0390e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4b34fe156455d26ee6ed67b61539f136bf4e439c
+refs/heads/master: 64e9159f5d2c4edf5fa6425031e556f8fddaf7e6
diff --git a/trunk/drivers/serial/serial_core.c b/trunk/drivers/serial/serial_core.c
index 53b03c629aff..951a75ea6e3e 100644
--- a/trunk/drivers/serial/serial_core.c
+++ b/trunk/drivers/serial/serial_core.c
@@ -1165,6 +1165,15 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
 	return ret;
 }
 
+static void uart_set_ldisc(struct tty_struct *tty, int ldisc)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+
+	if (port->ops->set_ldisc)
+		port->ops->set_ldisc(port);
+}
+
 static void uart_set_termios(struct tty_struct *tty,
 						struct ktermios *old_termios)
 {
@@ -2288,6 +2297,7 @@ static const struct tty_operations uart_ops = {
 	.unthrottle	= uart_unthrottle,
 	.send_xchar	= uart_send_xchar,
 	.set_termios	= uart_set_termios,
+	.set_ldisc	= uart_set_ldisc,
 	.stop		= uart_stop,
 	.start		= uart_start,
 	.hangup		= uart_hangup,
diff --git a/trunk/include/linux/serial_core.h b/trunk/include/linux/serial_core.h
index d32123ae08ad..d8f31de632c5 100644
--- a/trunk/include/linux/serial_core.h
+++ b/trunk/include/linux/serial_core.h
@@ -192,6 +192,7 @@ struct uart_ops {
 	void		(*shutdown)(struct uart_port *);
 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
 				       struct ktermios *old);
+	void		(*set_ldisc)(struct uart_port *);
 	void		(*pm)(struct uart_port *, unsigned int state,
 			      unsigned int oldstate);
 	int		(*set_wake)(struct uart_port *, unsigned int state);