Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[linux-2.6-omap-h63xx.git] / drivers / usb / serial / usb-serial.c

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 8be3f39891c71c705c61a8a3d95ff53e3289300b..080ade223d53fe1306206f8b0f93388f75c17246 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -269,28 +269,34 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
                return;
        }
 
-       --port->port.count;
-       if (port->port.count == 0)
+       if (port->port.count == 1)
                /* only call the device specific close if this
-                * port is being closed by the last owner */
+                * port is being closed by the last owner. Ensure we do
+                * this before we drop the port count. The call is protected
+                * by the port mutex
+                */
                port->serial->type->close(tty, port, filp);
 
-       if (port->port.count == (port->console? 1 : 0)) {
+       if (port->port.count == (port->console ? 2 : 1)) {
                struct tty_struct *tty = tty_port_tty_get(&port->port);
                if (tty) {
+                       /* We must do this before we drop the port count to
+                          zero. */
                        if (tty->driver_data)
                                tty->driver_data = NULL;
                        tty_port_tty_set(&port->port, NULL);
+                       tty_kref_put(tty);
                }
        }
 
-       if (port->port.count == 0) {
+       if (port->port.count == 1) {
                mutex_lock(&port->serial->disc_mutex);
                if (!port->serial->disconnected)
                        usb_autopm_put_interface(port->serial->interface);
                mutex_unlock(&port->serial->disc_mutex);
                module_put(port->serial->type->driver.owner);
        }
+       --port->port.count;
 
        mutex_unlock(&port->mutex);
        usb_serial_put(port->serial);
@@ -333,6 +339,10 @@ static int serial_chars_in_buffer(struct tty_struct *tty)
        dbg("%s = port %d", __func__, port->number);
 
        WARN_ON(!port->port.count);
+       /* if the device was unplugged then any remaining characters
+          fell out of the connector ;) */
+       if (port->serial->disconnected)
+               return 0;
        /* pass on to the driver specific version of this function */
        return port->serial->type->chars_in_buffer(tty);
 }
@@ -372,9 +382,7 @@ static int serial_ioctl(struct tty_struct *tty, struct file *file,
        /* pass on to the driver specific version of this function
           if it is available */
        if (port->serial->type->ioctl) {
-               lock_kernel();
                retval = port->serial->type->ioctl(tty, file, cmd, arg);
-               unlock_kernel();
        } else
                retval = -ENOIOCTLCMD;
        return retval;
@@ -403,11 +411,8 @@ static int serial_break(struct tty_struct *tty, int break_state)
        WARN_ON(!port->port.count);
        /* pass on to the driver specific version of this function
           if it is available */
-       if (port->serial->type->break_ctl) {
-               lock_kernel();
+       if (port->serial->type->break_ctl)
                port->serial->type->break_ctl(tty, break_state);
-               unlock_kernel();
-       }
        return 0;
 }