1 files changed, 30 insertions, 5 deletions

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index a817ced82835..d2d550549038 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -208,18 +208,23 @@ retry:
 	urb->transfer_buffer_length = count;
 	usb_serial_debug_data(debug, &port->dev, __func__, count,
 						urb->transfer_buffer);
+	spin_lock_irqsave(&port->lock, flags);
+	port->tx_bytes += count;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	clear_bit(i, &port->write_urbs_free);
 	result = usb_submit_urb(urb, GFP_ATOMIC);
 	if (result) {
 		dev_err(&port->dev, "%s - error submitting urb: %d\n",
 						__func__, result);
+		set_bit(i, &port->write_urbs_free);
+		spin_lock_irqsave(&port->lock, flags);
+		port->tx_bytes -= count;
+		spin_unlock_irqrestore(&port->lock, flags);
+
 		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
 		return result;
 	}
-	clear_bit(i, &port->write_urbs_free);
-
-	spin_lock_irqsave(&port->lock, flags);
-	port->tx_bytes += count;
-	spin_unlock_irqrestore(&port->lock, flags);
 
 	/* Try sending off another urb, unless in irq context (in which case
 	 * there will be no free urb). */
@@ -476,6 +481,26 @@ int usb_serial_handle_break(struct usb_serial_port *port)
 }
 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
 
+/**
+ *	usb_serial_handle_dcd_change - handle a change of carrier detect state
+ *	@port: usb_serial_port structure for the open port
+ *	@tty: tty_struct structure for the port
+ *	@status: new carrier detect status, nonzero if active
+ */
+void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
+				struct tty_struct *tty, unsigned int status)
+{
+	struct tty_port *port = &usb_port->port;
+
+	dbg("%s - port %d, status %d", __func__, usb_port->number, status);
+
+	if (status)
+		wake_up_interruptible(&port->open_wait);
+	else if (tty && !C_CLOCAL(tty))
+		tty_hangup(tty);
+}
+EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
+
 int usb_serial_generic_resume(struct usb_serial *serial)
 {
 	struct usb_serial_port *port;