Re: [PATCH 1/6] USB: serial: cp210x: fix control-characters error handling

[Greg KH]

On Fri, Jul 02, 2021 at 03:42:22PM +0200, Johan Hovold wrote:
> In the unlikely event that setting the software flow-control characters
> fails the other flow-control settings should still be updated.
> 
> Fixes: 7748feffcd80 ("USB: serial: cp210x: add support for software flow control")
> Cc: stable@xxxxxxxxxxxxxxx	# 5.11
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
>  drivers/usb/serial/cp210x.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
> index 09b845d0da41..b41e2c7649fb 100644
> --- a/drivers/usb/serial/cp210x.c
> +++ b/drivers/usb/serial/cp210x.c
> @@ -1217,9 +1217,7 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
>  		chars.bXonChar = START_CHAR(tty);
>  		chars.bXoffChar = STOP_CHAR(tty);
>  
> -		ret = cp210x_set_chars(port, &chars);
> -		if (ret)
> -			return;
> +		cp210x_set_chars(port, &chars);

What's the odds that someone tries to add the error checking back in
here, in a few years?  Can you put a comment here saying why you are not
checking it?

thanks,

greg k-h