[v3] serial: sc16is7xx: fix GPIO regression and rs485 improvements

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

Posted by Hugo Villeneuve 2 years, 8 months ago

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

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@dimonoff.com>
---
 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;
-- 
2.30.2

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

Posted by Ilpo Järvinen 2 years, 8 months ago

On Thu, 25 May 2023, Hugo Villeneuve wrote:

> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> 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@dimonoff.com>

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;
>

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

Posted by Hugo Villeneuve 2 years, 8 months ago

On Thu, 25 May 2023 14:02:19 +0300 (EEST)
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> wrote:

> On Thu, 25 May 2023, Hugo Villeneuve wrote:
> 
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > 
> > 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@dimonoff.com>
> 
> 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.

Hi,
there is a concrete problem when dumping the registers as the value read for bit SRESET is incorrect, but it doesn't impact running code.

I can remove the Fixes.

Hugo.


> > ---
> >  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;
> > 
>