Re: [PATCH v4 1/3] serial: sc16is7xx: announce support of SER_RS485_RTS_ON_SEND

[Hugo Villeneuve]

On Fri, 19 Apr 2024 15:45:01 +0300
Konstantin Pugin <rilian.la.te@xxxxx> wrote:

> From: Konstantin Pugin <ria.freelander@xxxxxxxxx>
> 
> The hardware supports both RTS_ON_SEND and RTS_AFTER_SEND modes, but
> after the commit 4afeced55baa ("serial: core: fix sanitizing check for
> RTS settings") we always end up with SER_RS485_RTS_AFTER_SEND set and
> always write to the register field SC16IS7XX_EFCR_RTS_INVERT_BIT, which
> breaks some hardware using these chips.

Hi Konstantin,
I am using RS-485 mode, and currently I may need SC16IS7XX_EFCR_RTS_INVERT_BIT to be set for my setup to work (not sure, must check this). Does it mean that with this patch it will be cleared? I am not sure by reading your commit message...

I need to look at this in more details, and test it on my hardware, which I will be able to do only next week. I will keep you posted.

Hugo.



> 
> Fixes: 267913ecf737 ("serial: sc16is7xx: Fill in rs485_supported")
> Signed-off-by: Konstantin Pugin <ria.freelander@xxxxxxxxx>
> ---
>  drivers/tty/serial/sc16is7xx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index 03cf30e20b75..dfcc804f558f 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1449,7 +1449,7 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
>  }
>  
>  static const struct serial_rs485 sc16is7xx_rs485_supported = {
> -	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
> +	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
>  	.delay_rts_before_send = 1,
>  	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
>  };
> -- 
> 2.34.1
> 
> 
> 


-- 
Hugo Villeneuve <hugo@xxxxxxxxxxx>