USB: ftdi_sio: fix TIOCSSERIAL baud_base handling

commit eb833a9e0972f60beb4ab8104ad7ef6bf30f02fc upstream.

Return EINVAL if new baud_base does not match the current one.

The baud_base is device specific and can not be changed. This restores
the old (pre-2005) behaviour which was changed due to a
misunderstanding regarding this fact (see
https://lkml.org/lkml/2005/1/20/84).

Reported-by: Torbjörn Lofterud <torbjorn@pi.nxs.se>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index ff3db5d..6a034b3 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1333,8 +1333,7 @@ static int set_serial_info(struct tty_struct *tty,
                goto check_and_exit;
        }
 
-       if ((new_serial.baud_base != priv->baud_base) &&
-           (new_serial.baud_base < 9600)) {
+       if (new_serial.baud_base != priv->baud_base) {
                mutex_unlock(&priv->cfg_lock);
                return -EINVAL;
        }