On Thu, Sep 14, 2017 at 01:30:12PM +0200, Oleksij Rempel wrote:
> From: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
>
> The only way of stopping the watchdog is by resetting it.
> Add the watchdog op for stopping the device and reset if
> a reset line is provided.
>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: linux-watchdog@xxxxxxxxxxxxxxx
> ---
>
> changes v2:
> - test if dw_wdt->rst is NULL instead of IS_ERR
>
> drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
> index 36be987ff9ef..a507f36302e1 100644
> --- a/drivers/watchdog/dw_wdt.c
> +++ b/drivers/watchdog/dw_wdt.c
> @@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
> return 0;
> }
>
> +static int dw_wdt_stop(struct watchdog_device *wdd)
> +{
> + struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
> +
> + if (!dw_wdt->rst) {
> + dev_warn(wdd->parent, "No reset line. Will not stop.\n");
> + return -EOPNOTSUPP;
Sorry, not the way to go. It now reports an error to user space when
there was none previously, and it still reboots the system. Plus, this
was a perfectly fine condition previously, and the reset line is optional.
It is not appropriate to generate a warning for a perfectly valid
condition.
You can not change behavior for existing users.
Guenter
> + }
> +
> + reset_control_assert(dw_wdt->rst);
> + reset_control_deassert(dw_wdt->rst);
> +
> + return 0;
> +}
> +
> static int dw_wdt_restart(struct watchdog_device *wdd,
> unsigned long action, void *data)
> {
> @@ -173,6 +188,7 @@ static const struct watchdog_info dw_wdt_ident = {
> static const struct watchdog_ops dw_wdt_ops = {
> .owner = THIS_MODULE,
> .start = dw_wdt_start,
> + .stop = dw_wdt_stop,
> .ping = dw_wdt_ping,
> .set_timeout = dw_wdt_set_timeout,
> .get_timeleft = dw_wdt_get_timeleft,
> --
> 2.11.0
>
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
