From: Guenter Roeck <linux@roeck-us.net>
To: Francesco Zanella <francesco.zanella@vimar.com>
Cc: linux-watchdog@vger.kernel.org, wim@linux-watchdog.org,
devicetree@vger.kernel.org, robh+dt@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] watchdog: gpio_wdt: add "start-at-boot" feature
Date: Wed, 21 Apr 2021 09:42:28 -0700 [thread overview]
Message-ID: <20210421164228.GB110463@roeck-us.net> (raw)
In-Reply-To: <20210421162621.24910-3-francesco.zanella@vimar.com>
On Wed, Apr 21, 2021 at 06:26:21PM +0200, Francesco Zanella wrote:
> If "start-at-boot" property is present in the device tree, start pinging
> hw watchdog at probe, in order to take advantage of kernel configs:
> - WATCHDOG_HANDLE_BOOT_ENABLED: Avoid possible reboot if hw watchdog was
> been enabled before the kernel (by uboot for example) and userspace
> doesn't take control of /dev/watchdog in time;
> - WATCHDOG_OPEN_TIMEOUT: Reboot if userspace doesn't take control of
> /dev/watchdog within the timeout.
>
> Signed-off-by: Francesco Zanella <francesco.zanella@vimar.com>
> ---
> drivers/watchdog/gpio_wdt.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
> index 0923201ce874..1e6f0322ab7a 100644
> --- a/drivers/watchdog/gpio_wdt.c
> +++ b/drivers/watchdog/gpio_wdt.c
> @@ -31,6 +31,7 @@ struct gpio_wdt_priv {
> struct gpio_desc *gpiod;
> bool state;
> bool always_running;
> + bool start_at_boot;
> unsigned int hw_algo;
> struct watchdog_device wdd;
> };
> @@ -147,6 +148,9 @@ static int gpio_wdt_probe(struct platform_device *pdev)
> priv->always_running = of_property_read_bool(np,
> "always-running");
>
> + priv->start_at_boot = of_property_read_bool(np,
> + "start-at-boot");
> +
> watchdog_set_drvdata(&priv->wdd, priv);
>
> priv->wdd.info = &gpio_wdt_ident;
> @@ -161,7 +165,7 @@ static int gpio_wdt_probe(struct platform_device *pdev)
>
> watchdog_stop_on_reboot(&priv->wdd);
>
> - if (priv->always_running)
> + if (priv->always_running || priv->start_at_boot)
> gpio_wdt_start(&priv->wdd);
So the only real difference to always_running is that always_running
doesn't stop the watchdog on close but keeps it running.
Does that really warrant another property ? Why not just use
always-running ?
The special use case of being able to stop the watchdog doesn't seem
to be worth the trouble. Please explain your use case.
Guenter
next prev parent reply other threads:[~2021-04-21 16:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 16:26 [PATCH 0/2] GPIO WDT "start-at-boot" property Francesco Zanella
2021-04-21 16:26 ` [PATCH 1/2] dt-bindings: watchdog: gpio-wdt: add "start-at-boot" Francesco Zanella
2021-04-21 16:37 ` Guenter Roeck
2021-04-22 16:28 ` Francesco Zanella
2021-04-21 16:26 ` [PATCH 2/2] watchdog: gpio_wdt: add "start-at-boot" feature Francesco Zanella
2021-04-21 16:42 ` Guenter Roeck [this message]
2021-04-22 16:28 ` Francesco Zanella
2021-04-22 18:05 ` Guenter Roeck
2021-04-23 9:47 ` Francesco Zanella
2021-04-23 11:36 ` Rasmus Villemoes
2021-04-23 14:24 ` Francesco Zanella
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