On Wed, 18 Jan 2012 01:46:00 +0100
Johan Hovold <jhovold@xxxxxxxxx> wrote:
> >From e4fbe1da98a05be0ea450decfc5a0efdd8a43afe Mon Sep 17 00:00:00 2001
> From: Johan Hovold <jhovold@xxxxxxxxx>
> Date: Wed, 18 Jan 2012 00:46:34 +0100
> Subject: [PATCH] USB: ftdi_sio: fix initial baud rate
>
> Fix regression introduced by commit b1ffb4c851f1 ("USB: Fix Corruption
> issue in USB ftdi driver ftdi_sio.c") which caused the termios settings
> to no longer be initialised at open. Consequently it was no longer
> possible to set the port to the default speed of 9600 baud without first
> changing to another baud rate and back again.
>
> Reported-by: Roland Ramthun <mail@xxxxxxxxxxxxxxxxx>
> Cc: stable <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
> ---
>
> Greg,
>
> It seems the commit causing the regression has been back-ported to a number of
> stable kernels.
>
> Thanks,
> Johan
>
>
> drivers/usb/serial/ftdi_sio.c | 7 +++++--
> 1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index 6a034b3..6a40b41 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c
> @@ -1823,6 +1823,7 @@ static int ftdi_sio_port_remove(struct
> usb_serial_port *port)
>
> static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
> {
> + struct ktermios dummy;
> struct usb_device *dev = port->serial->dev;
> struct ftdi_private *priv = usb_get_serial_port_data(port);
> int result;
> @@ -1841,8 +1842,10 @@ static int ftdi_open(struct tty_struct *tty,
> struct usb_serial_port *port)
> This is same behaviour as serial.c/rs_open() - Kuba */
>
> /* ftdi_set_termios will send usb control messages */
> - if (tty)
> - ftdi_set_termios(tty, port, tty->termios);
> + if (tty) {
> + memset(&dummy, 0, sizeof(dummy));
> + ftdi_set_termios(tty, port, &dummy);
> + }
>
> /* Start reading from the device */
> result = usb_serial_generic_open(tty, port);
> --
> 1.7.8
I've applied this patch on a 3.1.6 kernel and can confirm my hardware is working as expected again.
Thank you for the quick solution, Johan.
Roland
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
