Re: [PATCH v3 3/7] USB: serial: ftdi_sio: Extract SIO divisor code to function

[Johan Hovold <johan@kernel.org>]

On Sat, Sep 24, 2022 at 12:27:14PM +0200, Pali Rohár wrote:
> In preparation for following changes, extract divisor code for SIO chip
> into new function ftdi_sio_baud_to_divisor(), as is done for other
> chips.

Please spell out what you mean by "following changes".

You're also now using the new helper to set the fallback rate, which
should at least be mentioned as it looks like a separate and unnecessary
change currently.

> No functional change.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Tested-by: Marek Behún <kabel@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> ---
>  drivers/usb/serial/ftdi_sio.c | 45 ++++++++++++++++++++++++-----------
>  1 file changed, 31 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index bfa601fc14fe..fe8a7c5fa0e9 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c

> @@ -1314,23 +1342,12 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
>  		baud = 9600;
>  	switch (priv->chip_type) {
>  	case SIO: /* SIO chip */
> -		switch (baud) {
> -		case 300: div_value = ftdi_sio_b300; break;
> -		case 600: div_value = ftdi_sio_b600; break;
> -		case 1200: div_value = ftdi_sio_b1200; break;
> -		case 2400: div_value = ftdi_sio_b2400; break;
> -		case 4800: div_value = ftdi_sio_b4800; break;
> -		case 9600: div_value = ftdi_sio_b9600; break;
> -		case 19200: div_value = ftdi_sio_b19200; break;
> -		case 38400: div_value = ftdi_sio_b38400; break;
> -		case 57600: div_value = ftdi_sio_b57600;  break;
> -		case 115200: div_value = ftdi_sio_b115200; break;
> -		} /* baud */
> -		if (div_value == 0) {
> +		div_value = ftdi_sio_baud_to_divisor(baud);
> +		if (div_value == (u32)-1) {
>  			dev_dbg(dev, "%s - Baudrate (%d) requested is not supported\n",
>  				__func__,  baud);
> -			div_value = ftdi_sio_b9600;
>  			baud = 9600;
> +			div_value = ftdi_sio_baud_to_divisor(baud);
>  			div_okay = 0;
>  		}
>  		break;

This one too needs to be rebased, but you'll notice that.

Johan