1 files changed, 33 insertions, 31 deletions

diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index ffbe601cde2a..7d84a7647e81 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -5,9 +5,9 @@
  *      Copyright (C) 1999 - 2004
  *          Greg Kroah-Hartman (greg@kroah.com)
  *
- *      This program is free software; you can redistribute it and/or modify
- *      it under the terms of the GNU General Public License as published by
- *      the Free Software Foundation; either version 2 of the License.
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License version
+ *      2 as published by the Free Software Foundation.
  *
  * See Documentation/usb/usb-serial.txt for more information on using this driver
  *
@@ -273,7 +273,8 @@ struct visor_private {
         int bytes_in;
         int bytes_out;
         int outstanding_urbs;
-        int throttled;
+        unsigned char throttled;
+        unsigned char actually_throttled;
 };
 
 /* number of outstanding urbs to prevent userspace DoS from happening */
@@ -484,16 +485,17 @@ static void visor_write_bulk_callback (struct urb *urb)
 {
         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
         struct visor_private *priv = usb_get_serial_port_data(port);
+        int status = urb->status;
         unsigned long flags;
 
         /* free up the transfer buffer, as usb_free_urb() does not do this */
         kfree (urb->transfer_buffer);
 
         dbg("%s - port %d", __FUNCTION__, port->number);
-        
-        if (urb->status)
+
+        if (status)
                 dbg("%s - nonzero write bulk status received: %d",
-                    __FUNCTION__, urb->status);
+                    __FUNCTION__, status);
 
         spin_lock_irqsave(&priv->lock, flags);
         --priv->outstanding_urbs;
@@ -508,15 +510,16 @@ static void visor_read_bulk_callback (struct urb *urb)
         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
         struct visor_private *priv = usb_get_serial_port_data(port);
         unsigned char *data = urb->transfer_buffer;
+        int status = urb->status;
         struct tty_struct *tty;
-        unsigned long flags;
-        int throttled;
         int result;
+        int available_room;
 
         dbg("%s - port %d", __FUNCTION__, port->number);
 
-        if (urb->status) {
-                dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
+        if (status) {
+                dbg("%s - nonzero read bulk status received: %d",
+                    __FUNCTION__, status);
                 return;
         }
 
@@ -524,17 +527,20 @@ static void visor_read_bulk_callback (struct urb *urb)
 
         tty = port->tty;
         if (tty && urb->actual_length) {
-                tty_buffer_request_room(tty, urb->actual_length);
-                tty_insert_flip_string(tty, data, urb->actual_length);
-                tty_flip_buffer_push(tty);
+                available_room = tty_buffer_request_room(tty, urb->actual_length);
+                if (available_room) {
+                        tty_insert_flip_string(tty, data, available_room);
+                        tty_flip_buffer_push(tty);
+                }
+                spin_lock(&priv->lock);
+                priv->bytes_in += available_room;
+
+        } else {
+                spin_lock(&priv->lock);
         }
-        spin_lock_irqsave(&priv->lock, flags);
-        priv->bytes_in += urb->actual_length;
-        throttled = priv->throttled;
-        spin_unlock_irqrestore(&priv->lock, flags);
 
         /* Continue trying to always read if we should */
-        if (!throttled) {
+        if (!priv->throttled) {
                 usb_fill_bulk_urb (port->read_urb, port->serial->dev,
                                    usb_rcvbulkpipe(port->serial->dev,
                                                    port->bulk_in_endpointAddress),
@@ -544,16 +550,19 @@ static void visor_read_bulk_callback (struct urb *urb)
                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
                 if (result)
                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
+        } else {
+                priv->actually_throttled = 1;
         }
-        return;
+        spin_unlock(&priv->lock);
 }
 
 static void visor_read_int_callback (struct urb *urb)
 {
         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+        int status = urb->status;
         int result;
 
-        switch (urb->status) {
+        switch (status) {
         case 0:
                 /* success */
                 break;
@@ -562,11 +571,11 @@ static void visor_read_int_callback (struct urb *urb)
         case -ESHUTDOWN:
                 /* this urb is terminated, clean up */
                 dbg("%s - urb shutting down with status: %d",
-                    __FUNCTION__, urb->status);
+                    __FUNCTION__, status);
                 return;
         default:
                 dbg("%s - nonzero urb status received: %d",
-                    __FUNCTION__, urb->status);
+                    __FUNCTION__, status);
                 goto exit;
         }
 
@@ -608,6 +617,7 @@ static void visor_unthrottle (struct usb_serial_port *port)
         dbg("%s - port %d", __FUNCTION__, port->number);
         spin_lock_irqsave(&priv->lock, flags);
         priv->throttled = 0;
+        priv->actually_throttled = 0;
         spin_unlock_irqrestore(&priv->lock, flags);
 
         port->read_urb->dev = port->serial->dev;
@@ -938,14 +948,6 @@ static void visor_set_termios (struct usb_serial_port *port, struct ktermios *ol
         }
 
         cflag = port->tty->termios->c_cflag;
-        /* check that they really want us to change something */
-        if (old_termios) {
-                if ((cflag == old_termios->c_cflag) &&
-                    (RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) {
-                        dbg("%s - nothing to change...", __FUNCTION__);
-                        return;
-                }
-        }
 
         /* get the byte size */
         switch (cflag & CSIZE) {