The patch below does not apply to the 3.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4746b6c6efcdc3f5ef84f0bc2c39707c6b4e5e24 Mon Sep 17 00:00:00 2001 From: Johan Hovold <jhovold@xxxxxxxxx> Date: Sun, 5 May 2013 20:32:33 +0200 Subject: [PATCH] USB: serial: clean up chars_in_buffer 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 <jhovold@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 60caf9c..4753c00 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -359,20 +359,13 @@ 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\n", __func__); - 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) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html