Commit 4746b6c6efcdc3f5ef84f0bc2c39707c6b4e5e24 upstream. Backported for 3.9-stable. Adjusted context.
From: Johan Hovold <[email protected]> No need to grab disconnect mutex in chars_in_buffer now that no sub-driver is or should be querying hardware buffers anymore. (They should use wait_until_sent.) Signed-off-by: Johan Hovold <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Lingzhu Xiang <[email protected]> diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 42de53c..d0742e8 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -363,20 +363,13 @@ 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 (serial->disconnected) - count = 0; - else - count = serial->type->chars_in_buffer(tty); - mutex_unlock(&serial->disc_mutex); + return 0; - return count; + return serial->type->chars_in_buffer(tty); } static void serial_wait_until_sent(struct tty_struct *tty, int timeout) -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
