On 11/09/2015 01:55 AM, Alexander Stein wrote:
This notifier is required when the watchdog is configured as always running because in this case the watchdog will be triggered when the kernel panics at boot before any application could open the device, e.g. because the rootfs is broken. This should result in a resetting system. Thus we register a panic notifier which stops triggering the watchdog.
Shouldn't the timer be stopped instead ? Copying Uwe for additional input. Thanks, Guenter
Signed-off-by: Alexander Stein <[email protected]> --- drivers/watchdog/gpio_wdt.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index c7b8a06..aaa0815 100644 --- a/drivers/watchdog/gpio_wdt.c +++ b/drivers/watchdog/gpio_wdt.c @@ -37,6 +37,7 @@ struct gpio_wdt_priv { unsigned int hw_margin; unsigned long last_jiffies; struct notifier_block reboot_notifier; + struct notifier_block panic_notifier; struct timer_list timer; struct watchdog_device wdd; }; @@ -146,6 +147,17 @@ static int gpio_wdt_notify_sys(struct notifier_block *nb, unsigned long code, return NOTIFY_DONE; } +static int gpio_wdt_notify_panic(struct notifier_block *nb, unsigned long code, + void *unused) +{ + struct gpio_wdt_priv *priv = container_of(nb, struct gpio_wdt_priv, + panic_notifier); + + gpio_wdt_disable(priv); + + return NOTIFY_DONE; +} + static const struct watchdog_info gpio_wdt_ident = { .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, @@ -233,11 +245,19 @@ static int gpio_wdt_probe(struct platform_device *pdev) if (ret) goto error_unregister; + priv->panic_notifier.notifier_call = gpio_wdt_notify_panic; + ret = atomic_notifier_chain_register(&panic_notifier_list, + &priv->panic_notifier); + if (ret) + goto error_unregister_notify; + if (priv->always_running) gpio_wdt_start_impl(priv); return 0; +error_unregister_notify: + unregister_reboot_notifier(&priv->reboot_notifier); error_unregister: watchdog_unregister_device(&priv->wdd); return ret;
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