Re: [PATCH v9 02/10] serial: sc16is7xx: mark IOCONTROL register as volatile

From: Greg KH
Date: Mon Jul 31 2023 - 11:50:53 EST


On Tue, Jul 25, 2023 at 10:23:34AM -0400, 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,
> which is incorrect.
>
> Also, if IOCONTROL register is not a volatile register, the upcoming
> patch "serial: sc16is7xx: fix regression with GPIO configuration"
> doesn't work when setting some shared GPIO lines as modem control
> lines.
>
> Therefore mark IOCONTROL register as a volatile register.
>
> Cc: <stable@xxxxxxxxxxxxxxx> # 6.1.x

Why 6.1.y? What commit does this fix?

> Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> Reviewed-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx>
> Tested-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx>
> ---
> 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 8ae2afc76a9b..306ae512b38a 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;

Is this the same as this change:
https://lore.kernel.org/all/20230724034727.17335-1-hui.wang@xxxxxxxxxxxxx/

confused,

greg k-h