Re: [PATCH linux-next] USB: serial: ftdi_sio: remove the unneeded result variable

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Sep 12, 2022 at 01:38:27PM +0000, cgel.zte@gmail.com wrote:
> From: Xu Panda <xu.panda@zte.com.cn>
> 
> Return the value usb_control_msg() directly instead of storing
> it in another redundant variable.
> 
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
> ---
>  drivers/usb/serial/ftdi_sio.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index 0a1da579ead5..f02dcef69cb9 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c
> @@ -1394,7 +1394,6 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
>         u16 value;
>         u16 index;
>         u32 index_value;
> -       int rv;
> 
>         index_value = get_ftdi_divisor(tty, port);
>         value = (u16)index_value;
> @@ -1407,13 +1406,12 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
>                 index = (u16)((index << 8) | priv->interface);
>         }
> 
> -       rv = usb_control_msg(port->serial->dev,
> -                           usb_sndctrlpipe(port->serial->dev, 0),
> -                           FTDI_SIO_SET_BAUDRATE_REQUEST,
> -                           FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE,
> -                           value, index,
> -                           NULL, 0, WDR_SHORT_TIMEOUT);
> -       return rv;
> +       return usb_control_msg(port->serial->dev,
> +                              usb_sndctrlpipe(port->serial->dev, 0),
> +                              FTDI_SIO_SET_BAUDRATE_REQUEST,
> +                              FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE,
> +                              value, index,
> +                              NULL, 0, WDR_SHORT_TIMEOUT);
>  }

That's really not the correct use of the return value of
usb_control_msg().  Can you fix this up to properly handle the return
value, or better yet, use the usb_control_msg_send() call?

thanks,

greg k-h