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

From: Neil Armstrong
Date: Mon Sep 30 2019 - 04:17:01 EST


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>