The always-running (from linux,wdt-gpio.yaml) is abused by the BD9576
watchdog driver. It's defined meaning is "the watchdog is always running
and can not be stopped". The BD9576 watchdog driver has implemented it
as "start watchdog when loading the module and prevent it from being
stopped".
Furthermore, the implementation does not set the WDOG_HW_RUNNING when
enabling the watchdog due to the "always-running" at module loading.
This will end up resulting a watchdog timeout if the device is not
opened.
The culprit was pointed out by Guenter, discussion can be found from
https://lore.kernel.org/lkml/[email protected]/
Drop the invalid "always-running" handling.
Signed-off-by: Matti Vaittinen <[email protected]>
Reported-by: Guenter Roeck <[email protected]>
Fixes: b237bcac557a ("wdt: Support wdt on ROHM BD9576MUF and BD9573MUF")
---
drivers/watchdog/bd9576_wdt.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/drivers/watchdog/bd9576_wdt.c b/drivers/watchdog/bd9576_wdt.c
index 4a20e07fbb69..f00ea1b4e40b 100644
--- a/drivers/watchdog/bd9576_wdt.c
+++ b/drivers/watchdog/bd9576_wdt.c
@@ -29,7 +29,6 @@ struct bd9576_wdt_priv {
struct gpio_desc *gpiod_en;
struct device *dev;
struct regmap *regmap;
- bool always_running;
struct watchdog_device wdd;
};
@@ -62,10 +61,7 @@ static int bd9576_wdt_stop(struct watchdog_device *wdd)
{
struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
- if (!priv->always_running)
- bd9576_wdt_disable(priv);
- else
- set_bit(WDOG_HW_RUNNING, &wdd->status);
+ bd9576_wdt_disable(priv);
return 0;
}
@@ -264,9 +260,6 @@ static int bd9576_wdt_probe(struct platform_device *pdev)
if (ret)
return ret;
- priv->always_running = device_property_read_bool(dev->parent,
- "always-running");
-
watchdog_set_drvdata(&priv->wdd, priv);
priv->wdd.info = &bd957x_wdt_ident;
@@ -281,9 +274,6 @@ static int bd9576_wdt_probe(struct platform_device *pdev)
watchdog_stop_on_reboot(&priv->wdd);
- if (priv->always_running)
- bd9576_wdt_start(&priv->wdd);
-
return devm_watchdog_register_device(dev, &priv->wdd);
}
base-commit: 4cece764965020c22cff7665b18a012006359095
--
2.43.2
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]
On Mon, Apr 08, 2024 at 01:02:31PM +0300, Matti Vaittinen wrote:
> The always-running (from linux,wdt-gpio.yaml) is abused by the BD9576
> watchdog driver. It's defined meaning is "the watchdog is always running
> and can not be stopped". The BD9576 watchdog driver has implemented it
> as "start watchdog when loading the module and prevent it from being
> stopped".
>
> Furthermore, the implementation does not set the WDOG_HW_RUNNING when
> enabling the watchdog due to the "always-running" at module loading.
> This will end up resulting a watchdog timeout if the device is not
> opened.
>
> The culprit was pointed out by Guenter, discussion can be found from
> https://lore.kernel.org/lkml/[email protected]/
>
> Drop the invalid "always-running" handling.
>
> Signed-off-by: Matti Vaittinen <[email protected]>
> Reported-by: Guenter Roeck <[email protected]>
> Fixes: b237bcac557a ("wdt: Support wdt on ROHM BD9576MUF and BD9573MUF")
Reviewed-by: Guenter Roeck <[email protected]>
Guenter