diff options
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 64bda135ba7e..a19ed74d770d 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -361,15 +361,21 @@ static int serial_write_room(struct tty_struct *tty) static int serial_chars_in_buffer(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; + struct usb_serial *serial = port->serial; + int count = 0; dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number); + mutex_lock(&serial->disc_mutex); /* 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); + if (serial->disconnected) + count = 0; + else + count = serial->type->chars_in_buffer(tty); + mutex_unlock(&serial->disc_mutex); + + return count; } static void serial_throttle(struct tty_struct *tty) @@ -688,10 +694,20 @@ static int serial_carrier_raised(struct tty_port *port) static void serial_dtr_rts(struct tty_port *port, int on) { struct usb_serial_port *p = container_of(port, struct usb_serial_port, port); - struct usb_serial_driver *drv = p->serial->type; + struct usb_serial *serial = p->serial; + struct usb_serial_driver *drv = serial->type; - if (drv->dtr_rts) + if (!drv->dtr_rts) + return; + /* + * Work-around bug in the tty-layer which can result in dtr_rts + * being called after a disconnect (and tty_unregister_device + * has returned). Remove once bug has been squashed. + */ + mutex_lock(&serial->disc_mutex); + if (!serial->disconnected) drv->dtr_rts(p, on); + mutex_unlock(&serial->disc_mutex); } static const struct tty_port_operations serial_port_ops = { |