[v2,3/3] ACPI / watchdog: Set default timeout in probe
diff mbox series

Message ID 20200212145941.32914-4-mika.westerberg@linux.intel.com
State Awaiting Upstream
Delegated to: Rafael Wysocki
Headers show
Series
  • ACPI / watchdog: Fix two reported issues
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Commit Message

Mika Westerberg Feb. 12, 2020, 2:59 p.m. UTC
If the BIOS default timeout for the watchdog is too small userspace may
not have enough time to configure new timeout after opening the device
before the system is already reset. For this reason program default
timeout of 30 seconds in the driver probe and allow userspace to change
this from command line or through module parameter (wdat_wdt.timeout).

Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/watchdog/wdat_wdt.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Comments

Jean Delvare Feb. 12, 2020, 4:04 p.m. UTC | #1
On Wed, 12 Feb 2020 17:59:41 +0300, Mika Westerberg wrote:
> If the BIOS default timeout for the watchdog is too small userspace may
> not have enough time to configure new timeout after opening the device
> before the system is already reset. For this reason program default
> timeout of 30 seconds in the driver probe and allow userspace to change
> this from command line or through module parameter (wdat_wdt.timeout).
> 
> Reported-by: Jean Delvare <jdelvare@suse.de>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
>  drivers/watchdog/wdat_wdt.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
> index e1b1fcfc02af..3065dd670a18 100644
> --- a/drivers/watchdog/wdat_wdt.c
> +++ b/drivers/watchdog/wdat_wdt.c
> @@ -54,6 +54,13 @@ module_param(nowayout, bool, 0);
>  MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
>  		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>  
> +#define WDAT_DEFAULT_TIMEOUT	30
> +
> +static int timeout = WDAT_DEFAULT_TIMEOUT;
> +module_param(timeout, int, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
> +		 __MODULE_STRING(WDAT_DEFAULT_TIMEOUT) ")");
> +
>  static int wdat_wdt_read(struct wdat_wdt *wdat,
>  	 const struct wdat_instruction *instr, u32 *value)
>  {
> @@ -438,6 +445,22 @@ static int wdat_wdt_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, wdat);
>  
> +	/*
> +	 * Set initial timeout so that userspace has time to configure the
> +	 * watchdog properly after it has opened the device. In some cases
> +	 * the BIOS default is too short and causes immediate reboot.
> +	 */
> +	if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
> +	    timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
> +		dev_warn(dev, "Invalid timeout %d given, using %d\n",
> +			 timeout, WDAT_DEFAULT_TIMEOUT);
> +		timeout = WDAT_DEFAULT_TIMEOUT;
> +	}
> +
> +	ret = wdat_wdt_set_timeout(&wdat->wdd, timeout);
> +	if (ret)
> +		return ret;
> +
>  	watchdog_set_nowayout(&wdat->wdd, nowayout);
>  	return devm_watchdog_register_device(dev, &wdat->wdd);
>  }

Reviewed-by: Jean Delvare <jdelvare@suse.de>

Thanks Mika!

Patch
diff mbox series

diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
index e1b1fcfc02af..3065dd670a18 100644
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -54,6 +54,13 @@  module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+#define WDAT_DEFAULT_TIMEOUT	30
+
+static int timeout = WDAT_DEFAULT_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
+		 __MODULE_STRING(WDAT_DEFAULT_TIMEOUT) ")");
+
 static int wdat_wdt_read(struct wdat_wdt *wdat,
 	 const struct wdat_instruction *instr, u32 *value)
 {
@@ -438,6 +445,22 @@  static int wdat_wdt_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, wdat);
 
+	/*
+	 * Set initial timeout so that userspace has time to configure the
+	 * watchdog properly after it has opened the device. In some cases
+	 * the BIOS default is too short and causes immediate reboot.
+	 */
+	if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
+	    timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
+		dev_warn(dev, "Invalid timeout %d given, using %d\n",
+			 timeout, WDAT_DEFAULT_TIMEOUT);
+		timeout = WDAT_DEFAULT_TIMEOUT;
+	}
+
+	ret = wdat_wdt_set_timeout(&wdat->wdd, timeout);
+	if (ret)
+		return ret;
+
 	watchdog_set_nowayout(&wdat->wdd, nowayout);
 	return devm_watchdog_register_device(dev, &wdat->wdd);
 }