diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c
index b57cf841c5b6..4b2a19757b4d 100644
--- a/drivers/usb/serial/ssu100.c
+++ b/drivers/usb/serial/ssu100.c
@@ -61,7 +61,6 @@ struct ssu100_port_private {
 	spinlock_t status_lock;
 	u8 shadowLSR;
 	u8 shadowMSR;
-	wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
 	struct async_icount icount;
 };
 
@@ -355,8 +354,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 	spin_unlock_irqrestore(&priv->status_lock, flags);
 
 	while (1) {
-		wait_event_interruptible(priv->delta_msr_wait,
-					 ((priv->icount.rng != prev.rng) ||
+		wait_event_interruptible(port->delta_msr_wait,
+					 (port->serial->disconnected ||
+					  (priv->icount.rng != prev.rng) ||
 					  (priv->icount.dsr != prev.dsr) ||
 					  (priv->icount.dcd != prev.dcd) ||
 					  (priv->icount.cts != prev.cts)));
@@ -364,6 +364,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 		if (signal_pending(current))
 			return -ERESTARTSYS;
 
+		if (port->serial->disconnected)
+			return -EIO;
+
 		spin_lock_irqsave(&priv->status_lock, flags);
 		cur = priv->icount;
 		spin_unlock_irqrestore(&priv->status_lock, flags);
@@ -445,7 +448,6 @@ static int ssu100_port_probe(struct usb_serial_port *port)
 		return -ENOMEM;
 
 	spin_lock_init(&priv->status_lock);
-	init_waitqueue_head(&priv->delta_msr_wait);
 
 	usb_set_serial_port_data(port, priv);
 
@@ -537,7 +539,7 @@ static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
 			priv->icount.dcd++;
 		if (msr & UART_MSR_TERI)
 			priv->icount.rng++;
-		wake_up_interruptible(&priv->delta_msr_wait);
+		wake_up_interruptible(&port->delta_msr_wait);
 	}
 }