Re: [PATCH v3 03/11] serial: sc16is7xx: mark IOCONTROL register as volatile

[Ilpo Järvinen]

On Thu, 25 May 2023, Hugo Villeneuve wrote:

> From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> 
> Bit SRESET (3) is cleared when a reset operation is completed. Having
> the IOCONTROL register as non-volatile will always read SRESET as 1.
> Therefore mark IOCONTROL register as a volatile register.
> 
> Fixes: dfeae619d781 ("serial: sc16is7xx")
> Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

What is the impact of this problem? That is, what doesn't work? I only see 
writes to SC16IS7XX_IOCONTROL_REG. If there are no concrete problems 
fixed, don't put Fixes tag.

-- 
 i.

> ---
>  drivers/tty/serial/sc16is7xx.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index 00054bb49780..a7c4da3cfd2b 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -488,6 +488,7 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
>  	case SC16IS7XX_TXLVL_REG:
>  	case SC16IS7XX_RXLVL_REG:
>  	case SC16IS7XX_IOSTATE_REG:
> +	case SC16IS7XX_IOCONTROL_REG:
>  		return true;
>  	default:
>  		break;
>