1 files changed, 20 insertions, 16 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index ff8605b4b4be..02e7f2d32d52 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -75,7 +75,8 @@ struct ftdi_private {
 	unsigned long last_dtr_rts;	/* saved modem control outputs */
 	struct async_icount	icount;
 	wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
-	char prev_status, diff_status;        /* Used for TIOCMIWAIT */
+	char prev_status;        /* Used for TIOCMIWAIT */
+	bool dev_gone;        /* Used to abort TIOCMIWAIT */
 	char transmit_empty;	/* If transmitter is empty or not */
 	struct usb_serial_port *port;
 	__u16 interface;	/* FT2232C, FT2232H or FT4232H port interface
@@ -1681,6 +1682,7 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
 	init_waitqueue_head(&priv->delta_msr_wait);
 
 	priv->flags = ASYNC_LOW_LATENCY;
+	priv->dev_gone = false;
 
 	if (quirk && quirk->port_probe)
 		quirk->port_probe(priv);
@@ -1839,6 +1841,9 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)
 
 	dbg("%s", __func__);
 
+	priv->dev_gone = true;
+	wake_up_interruptible_all(&priv->delta_msr_wait);
+
 	remove_sysfs_attrs(port);
 
 	kref_put(&priv->kref, ftdi_sio_priv_release);
@@ -1982,17 +1987,19 @@ static int ftdi_process_packet(struct tty_struct *tty,
 	   N.B. packet may be processed more than once, but differences
 	   are only processed once.  */
 	status = packet[0] & FTDI_STATUS_B0_MASK;
-	if (status & FTDI_RS0_CTS)
-		priv->icount.cts++;
-	if (status & FTDI_RS0_DSR)
-		priv->icount.dsr++;
-	if (status & FTDI_RS0_RI)
-		priv->icount.rng++;
-	if (status & FTDI_RS0_RLSD)
-		priv->icount.dcd++;
 	if (status != priv->prev_status) {
-		priv->diff_status |= status ^ priv->prev_status;
-		wake_up_interruptible(&priv->delta_msr_wait);
+		char diff_status = status ^ priv->prev_status;
+
+		if (diff_status & FTDI_RS0_CTS)
+			priv->icount.cts++;
+		if (diff_status & FTDI_RS0_DSR)
+			priv->icount.dsr++;
+		if (diff_status & FTDI_RS0_RI)
+			priv->icount.rng++;
+		if (diff_status & FTDI_RS0_RLSD)
+			priv->icount.dcd++;
+
+		wake_up_interruptible_all(&priv->delta_msr_wait);
 		priv->prev_status = status;
 	}
 
@@ -2395,15 +2402,12 @@ static int ftdi_ioctl(struct tty_struct *tty,
 	 */
 	case TIOCMIWAIT:
 		cprev = priv->icount;
-		while (1) {
+		while (!priv->dev_gone) {
 			interruptible_sleep_on(&priv->delta_msr_wait);
 			/* see if a signal did it */
 			if (signal_pending(current))
 				return -ERESTARTSYS;
 			cnow = priv->icount;
-			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
-			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
-				return -EIO; /* no change => error */
 			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
@@ -2412,7 +2416,7 @@ static int ftdi_ioctl(struct tty_struct *tty,
 			}
 			cprev = cnow;
 		}
-		/* not reached */
+		return -EIO;
 		break;
 	case TIOCSERGETLSR:
 		return get_lsr_info(port, (struct serial_struct __user *)arg);