USB: ftdi_sio: fix TIOCSSERIAL baud_base handling

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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 01b6404df395..ff5a8e172a34 100644
--- 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;
         }