1 files changed, 19 insertions, 27 deletions

diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index b6911757c855..06d5a60be2c4 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -114,8 +114,6 @@ struct mct_u232_private {
 	unsigned char	     last_msr;      /* Modem Status Register */
 	unsigned int	     rx_flags;      /* Throttling flags */
 	struct async_icount  icount;
-	wait_queue_head_t    msr_wait;	/* for handling sleeping while waiting
-						for msr change to happen */
 };
 
 #define THROTTLED		0x01
@@ -409,7 +407,6 @@ static int mct_u232_port_probe(struct usb_serial_port *port)
 		return -ENOMEM;
 
 	spin_lock_init(&priv->lock);
-	init_waitqueue_head(&priv->msr_wait);
 
 	usb_set_serial_port_data(port, priv);
 
@@ -499,19 +496,15 @@ static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
 	unsigned int control_state;
 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
 
-	mutex_lock(&port->serial->disc_mutex);
-	if (!port->serial->disconnected) {
-		/* drop DTR and RTS */
-		spin_lock_irq(&priv->lock);
-		if (on)
-			priv->control_state |= TIOCM_DTR | TIOCM_RTS;
-		else
-			priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
-		control_state = priv->control_state;
-		spin_unlock_irq(&priv->lock);
-		mct_u232_set_modem_ctrl(port, control_state);
-	}
-	mutex_unlock(&port->serial->disc_mutex);
+	spin_lock_irq(&priv->lock);
+	if (on)
+		priv->control_state |= TIOCM_DTR | TIOCM_RTS;
+	else
+		priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
+	control_state = priv->control_state;
+	spin_unlock_irq(&priv->lock);
+
+	mct_u232_set_modem_ctrl(port, control_state);
 }
 
 static void mct_u232_close(struct usb_serial_port *port)
@@ -531,7 +524,6 @@ static void mct_u232_read_int_callback(struct urb *urb)
 {
 	struct usb_serial_port *port = urb->context;
 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
-	struct tty_struct *tty;
 	unsigned char *data = urb->transfer_buffer;
 	int retval;
 	int status = urb->status;
@@ -561,13 +553,9 @@ static void mct_u232_read_int_callback(struct urb *urb)
 	 */
 	if (urb->transfer_buffer_length > 2) {
 		if (urb->actual_length) {
-			tty = tty_port_tty_get(&port->port);
-			if (tty) {
-				tty_insert_flip_string(tty, data,
-						urb->actual_length);
-				tty_flip_buffer_push(tty);
-			}
-			tty_kref_put(tty);
+			tty_insert_flip_string(&port->port, data,
+					urb->actual_length);
+			tty_flip_buffer_push(&port->port);
 		}
 		goto exit;
 	}
@@ -610,7 +598,7 @@ static void mct_u232_read_int_callback(struct urb *urb)
 		tty_kref_put(tty);
 	}
 #endif
-	wake_up_interruptible(&priv->msr_wait);
+	wake_up_interruptible(&port->delta_msr_wait);
 	spin_unlock_irqrestore(&priv->lock, flags);
 exit:
 	retval = usb_submit_urb(urb, GFP_ATOMIC);
@@ -819,13 +807,17 @@ static int  mct_u232_ioctl(struct tty_struct *tty,
 		cprev = mct_u232_port->icount;
 		spin_unlock_irqrestore(&mct_u232_port->lock, flags);
 		for ( ; ; ) {
-			prepare_to_wait(&mct_u232_port->msr_wait,
+			prepare_to_wait(&port->delta_msr_wait,
 					&wait, TASK_INTERRUPTIBLE);
 			schedule();
-			finish_wait(&mct_u232_port->msr_wait, &wait);
+			finish_wait(&port->delta_msr_wait, &wait);
 			/* see if a signal did it */
 			if (signal_pending(current))
 				return -ERESTARTSYS;
+
+			if (port->serial->disconnected)
+				return -EIO;
+
 			spin_lock_irqsave(&mct_u232_port->lock, flags);
 			cnow = mct_u232_port->icount;
 			spin_unlock_irqrestore(&mct_u232_port->lock, flags);