diff options
| author | Johan Hovold <jhovold@gmail.com> | 2013-01-14 16:52:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-18 15:45:17 -0800 |
| commit | 810360a03597afc0d43a45798a52cfb69b8453d3 (patch) | |
| tree | 977253346afd738d334a73de671cbd9f2102d809 /drivers/usb/serial | |
| parent | fcdb6a21903bcab0b5f788ba7eb0c31dd06040fd (diff) | |
USB: serial: grab disconnect mutex in chars_in_buffer
Grab disconnect mutex in chars_in_buffer before checking disconnected
flag or calling driver specific function.
This allows subdrivers to query any hardware buffer status without
having to handle the locking themselves.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial')
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 64bda135ba7..0a17f594255 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) |