[PATCH 0/5 v2] watchdog: meson_gxbb_wdt: improve

[PATCH 0/5 v2] watchdog: meson_gxbb_wdt: improve

[Artem Lapkin]

Try to improve meson_gxbb_wdt driver to common view:

* Remove watchdog_stop_on_reboot (still can be activated by
watchdog.stop_on_reboot=1) i think this driver configuration more useful
becouse we can get reboot waranty for abnormal situations on shutdown stage

* Added timeout module param same as in other modules
* Added nowayout module param same as in other moduels
* Added missed watchdog_stop_on_unregister call
* Print watchdog success driver start status notification

Artem Lapkin (5):
  watchdog: meson_gxbb_wdt: remove watchdog_stop_on_reboot
  watchdog: meson_gxbb_wdt: add timeout module param
  watchdog: meson_gxbb_wdt: add nowayout module param
  watchdog: meson_gxbb_wdt: add stop_on_unregister
  watchdog: meson_gxbb_wdt: add register device status notification

 drivers/watchdog/meson_gxbb_wdt.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH 1/5] watchdog: meson_gxbb_wdt: remove watchdog_stop_on_reboot

[Artem Lapkin]

Remove watchdog_stop_on_reboot (still can be activated by
watchdog.stop_on_reboot=1) i think this driver configuration more useful
becouse we can get reboot waranty for abnormal situations on shutdown stage

Signed-off-by: Artem Lapkin <art@khadas.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 5a9ca10fbcfa..3f86530c33b0 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -186,7 +186,6 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
 
-	watchdog_stop_on_reboot(&data->wdt_dev);
 	return devm_watchdog_register_device(dev, &data->wdt_dev);
 }
 
-- 
2.25.1

[PATCH 2/5] watchdog: meson_gxbb_wdt: add timeout module param

[Artem Lapkin]

Added timeout module param same as in other modules

Signed-off-by: Artem Lapkin <art@khadas.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 3f86530c33b0..ecd1fc6f48ba 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -29,6 +29,11 @@
 #define GXBB_WDT_TCNT_SETUP_MASK		(BIT(16) - 1)
 #define GXBB_WDT_TCNT_CNT_SHIFT			16
 
+static unsigned int timeout = DEFAULT_TIMEOUT;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
+		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+
 struct meson_gxbb_wdt {
 	void __iomem *reg_base;
 	struct watchdog_device wdt_dev;
@@ -174,7 +179,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
 	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
 	data->wdt_dev.min_timeout = 1;
-	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
+	data->wdt_dev.timeout = timeout;
 	watchdog_set_drvdata(&data->wdt_dev, data);
 
 	/* Setup with 1ms timebase */
-- 
2.25.1

[PATCH 3/5] watchdog: meson_gxbb_wdt: add nowayout module param

[Artem Lapkin]

Added nowayout module param same as in other moduels

Signed-off-by: Artem Lapkin <art@khadas.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index ecd1fc6f48ba..0bf5dccf70b1 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -34,6 +34,11 @@ module_param(timeout, uint, 0);
 MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
 		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
 
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
 struct meson_gxbb_wdt {
 	void __iomem *reg_base;
 	struct watchdog_device wdt_dev;
@@ -190,6 +195,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 		data->reg_base + GXBB_WDT_CTRL_REG);
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
+	watchdog_set_nowayout(&data->wdt_dev, nowayout);
 
 	return devm_watchdog_register_device(dev, &data->wdt_dev);
 }
-- 
2.25.1

[PATCH 4/5] watchdog: meson_gxbb_wdt: add stop_on_unregister

[Artem Lapkin]

Added missed watchdog_stop_on_unregister call

Signed-off-by: Artem Lapkin <art@khadas.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 0bf5dccf70b1..2dbe254e5122 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -196,6 +196,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
 	watchdog_set_nowayout(&data->wdt_dev, nowayout);
+	watchdog_stop_on_unregister(&data->wdt_dev);
 
 	return devm_watchdog_register_device(dev, &data->wdt_dev);
 }
-- 
2.25.1

[PATCH 5/5] watchdog: meson_gxbb_wdt: add register device status notification

[Artem Lapkin]

Print watchdog success driver start status notification

Signed-off-by: Artem Lapkin <art@khadas.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 2dbe254e5122..750b304b460d 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -198,7 +198,14 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 	watchdog_set_nowayout(&data->wdt_dev, nowayout);
 	watchdog_stop_on_unregister(&data->wdt_dev);
 
-	return devm_watchdog_register_device(dev, &data->wdt_dev);
+	ret = devm_watchdog_register_device(dev, &data->wdt_dev);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
+		 data->wdt_dev.timeout, nowayout);
+
+	return ret;
 }
 
 static struct platform_driver meson_gxbb_wdt_driver = {
-- 
2.25.1

Re: [PATCH 1/5] watchdog: meson_gxbb_wdt: remove watchdog_stop_on_reboot

[Guenter Roeck]

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Remove watchdog_stop_on_reboot (still can be activated by
> watchdog.stop_on_reboot=1) i think this driver configuration more useful
> becouse we can get reboot waranty for abnormal situations on shutdown stage
> 

This is personal opinion. Driver authors would have to agree.

Guenter

> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 5a9ca10fbcfa..3f86530c33b0 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -186,7 +186,6 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   
>   	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
>   
> -	watchdog_stop_on_reboot(&data->wdt_dev);
>   	return devm_watchdog_register_device(dev, &data->wdt_dev);
>   }
>   
> 

Re: [PATCH 2/5] watchdog: meson_gxbb_wdt: add timeout module param

[Guenter Roeck]

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Added timeout module param same as in other modules
> 
> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 3f86530c33b0..ecd1fc6f48ba 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -29,6 +29,11 @@
>   #define GXBB_WDT_TCNT_SETUP_MASK		(BIT(16) - 1)
>   #define GXBB_WDT_TCNT_CNT_SHIFT			16
>   
> +static unsigned int timeout = DEFAULT_TIMEOUT;
> +module_param(timeout, uint, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
> +		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> +
>   struct meson_gxbb_wdt {
>   	void __iomem *reg_base;
>   	struct watchdog_device wdt_dev;
> @@ -174,7 +179,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
>   	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
>   	data->wdt_dev.min_timeout = 1;
> -	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
> +	data->wdt_dev.timeout = timeout;

This is wrong. A timeout module parameter should be set with a call to
watchdog_init_timeout(), the initial value should be 0, and data->wdt_dev.timeout
should be kept as-is. This ensures that the module parameter is validated.

Guenter

>   	watchdog_set_drvdata(&data->wdt_dev, data);
>   
>   	/* Setup with 1ms timebase */
> 

Re: [PATCH 3/5] watchdog: meson_gxbb_wdt: add nowayout module param

[Guenter Roeck]

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Added nowayout module param same as in other moduels

Please use complete sentences and words, check your spelling (modules),
and refrain from irrelevant statements such as "same as in other moduels".

"Add nowayout module parameter" is sufficient here.

> 
> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index ecd1fc6f48ba..0bf5dccf70b1 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -34,6 +34,11 @@ module_param(timeout, uint, 0);
>   MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
>   		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
>   
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="

'(' missing before 'default'

> +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
>   struct meson_gxbb_wdt {
>   	void __iomem *reg_base;
>   	struct watchdog_device wdt_dev;
> @@ -190,6 +195,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   		data->reg_base + GXBB_WDT_CTRL_REG);
>   
>   	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
> +	watchdog_set_nowayout(&data->wdt_dev, nowayout);
>   
>   	return devm_watchdog_register_device(dev, &data->wdt_dev);
>   }
> 

Re: [PATCH 4/5] watchdog: meson_gxbb_wdt: add stop_on_unregister

[Guenter Roeck]

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Added missed watchdog_stop_on_unregister call
> 

This is again personal opinion and needs an acknowledgement
by driver authors. It is only necessary if one wants to support
that the watchdog is force-stopped by killing the watchdog daemon
(which leaves the watchdog running) and subsequently unloading
the driver. The call is not 'missing'; otherwise the core could
just do it. For that reason it should not be added with the argument
that it would be 'missing'. This will require a better argument.
Why is that call needed ? What is the use case ?

Guenter

> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 0bf5dccf70b1..2dbe254e5122 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -196,6 +196,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   
>   	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
>   	watchdog_set_nowayout(&data->wdt_dev, nowayout);
> +	watchdog_stop_on_unregister(&data->wdt_dev);
>   
>   	return devm_watchdog_register_device(dev, &data->wdt_dev);
>   }
> 

Re: [PATCH 5/5] watchdog: meson_gxbb_wdt: add register device status notification

[Guenter Roeck]

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Print watchdog success driver start status notification
> 

Another personal opinion: The driver author decided that the message is
not needed (which matches my personal opinion). I'd rather see all those
messages either go away or moved to the core. Either case, this one is
misleading: The watchdog is _not_ enabled. The watchdog driver is loaded,
which is different.

Guenter

> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 2dbe254e5122..750b304b460d 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -198,7 +198,14 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   	watchdog_set_nowayout(&data->wdt_dev, nowayout);
>   	watchdog_stop_on_unregister(&data->wdt_dev);
>   
> -	return devm_watchdog_register_device(dev, &data->wdt_dev);
> +	ret = devm_watchdog_register_device(dev, &data->wdt_dev);
> +	if (ret)
> +		return ret;
> +
> +	dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
> +		 data->wdt_dev.timeout, nowayout);
> +
> +	return ret;
>   }
>   
>   static struct platform_driver meson_gxbb_wdt_driver = {
>