Re: [PATCH] watchdog: meson: Fix the wrong value of left time

[Neil Armstrong]

On 29/09/2019 12:53, Xingyu Chen wrote:
> The left time value is wrong when we get it by sysfs. The left time value
> should be equal to preset timeout value minus elapsed time value. According
> to the Meson-GXB/GXL datasheets which can be found at [0], the timeout value
> is saved to BIT[0-15] of the WATCHDOG_TCNT, and elapsed time value is saved
> to BIT[16-31] of the WATCHDOG_TCNT.
> 
> [0]: http://linux-meson.com
> 
> Fixes: 683fa50f0e18 ("watchdog: Add Meson GXBB Watchdog Driver")
> Signed-off-by: Xingyu Chen <xingyu.chen@xxxxxxxxxxx>
> ---
>  drivers/watchdog/meson_gxbb_wdt.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index d17c1a6..5a9ca10 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -89,8 +89,8 @@ static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
>  
>  	reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
>  
> -	return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) -
> -		(reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
> +	return ((reg & GXBB_WDT_TCNT_SETUP_MASK) -
> +		(reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000;
>  }
>  
>  static const struct watchdog_ops meson_gxbb_wdt_ops = {
> 

Acked-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>