diff mbox series

[v9,3/9] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()

Message ID 20240531065723.1085423-4-claudiu.beznea.uj@bp.renesas.com
State New
Headers show
Series watchdog: rzg2l_wdt: Add support for RZ/G3S | expand

Commit Message

claudiu beznea May 31, 2024, 6:57 a.m. UTC
From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

pm_runtime_get_sync() may return with error. In case it returns with error
dev->power.usage_count needs to be decremented. pm_runtime_resume_and_get()
takes care of this. Thus use it.

Along with it the rzg2l_wdt_set_timeout() function was updated to
propagate the result of rzg2l_wdt_start() to its caller.

Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---

Changes in v9:
- collected Guenter's Rb tag

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- propagate the return code of rzg2l_wdt_start() to it's callers


 drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Biju Das July 8, 2024, 5:46 a.m. UTC | #1
Hi Claudiu,

> -----Original Message-----
> From: Claudiu <claudiu.beznea@tuxon.dev>
> Sent: Friday, May 31, 2024 7:57 AM
> Subject: [PATCH v9 3/9] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
> 
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> pm_runtime_get_sync() may return with error. In case it returns with error
> dev->power.usage_count needs to be decremented.
> dev->pm_runtime_resume_and_get()
> takes care of this. Thus use it.
> 
> Along with it the rzg2l_wdt_set_timeout() function was updated to propagate the result of
> rzg2l_wdt_start() to its caller.
> 
> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> 
> Changes in v9:
> - collected Guenter's Rb tag
> 
> Changes in v8:
> - none
> 
> Changes in v7:
> - none
> 
> Changes in v6:
> - none
> 
> Changes in v5:
> - none
> 
> Changes in v4:
> - none
> 
> Changes in v3:
> - none
> 
> Changes in v2:
> - propagate the return code of rzg2l_wdt_start() to it's callers
> 
> 
>  drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index
> 1741f98ca67c..d87d4f50180c 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -123,8 +123,11 @@ static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev)  static int
> rzg2l_wdt_start(struct watchdog_device *wdev)  {
>  	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	int ret;
> 
> -	pm_runtime_get_sync(wdev->parent);
> +	ret = pm_runtime_resume_and_get(wdev->parent);
> +	if (ret)
> +		return ret;

Checking ret will lead to imbalance. It should be ret < 0 as ret = 1 corresponds to RPM_ACTIVE and the API does not call put() when ret = 1; see [1] and [2]

[1] https://elixir.bootlin.com/linux/v6.10-rc6/source/drivers/base/power/runtime.c#L778

[2] https://elixir.bootlin.com/linux/v6.10-rc6/source/include/linux/pm_runtime.h#L431

Cheers,
Biju
Biju Das July 8, 2024, 9:20 a.m. UTC | #2
> Subject: RE: [PATCH v9 3/9] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
> 
> Hi Claudiu,
> 
> > -----Original Message-----
> > From: Claudiu <claudiu.beznea@tuxon.dev>
> > Sent: Friday, May 31, 2024 7:57 AM
> > Subject: [PATCH v9 3/9] watchdog: rzg2l_wdt: Use
> > pm_runtime_resume_and_get()
> >
> > From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> >
> > pm_runtime_get_sync() may return with error. In case it returns with
> > error
> > dev->power.usage_count needs to be decremented.
> > dev->pm_runtime_resume_and_get()
> > takes care of this. Thus use it.
> >
> > Along with it the rzg2l_wdt_set_timeout() function was updated to
> > propagate the result of
> > rzg2l_wdt_start() to its caller.
> >
> > Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
> > Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> > ---
> >
> > Changes in v9:
> > - collected Guenter's Rb tag
> >
> > Changes in v8:
> > - none
> >
> > Changes in v7:
> > - none
> >
> > Changes in v6:
> > - none
> >
> > Changes in v5:
> > - none
> >
> > Changes in v4:
> > - none
> >
> > Changes in v3:
> > - none
> >
> > Changes in v2:
> > - propagate the return code of rzg2l_wdt_start() to it's callers
> >
> >
> >  drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
> >  1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/watchdog/rzg2l_wdt.c
> > b/drivers/watchdog/rzg2l_wdt.c index 1741f98ca67c..d87d4f50180c 100644
> > --- a/drivers/watchdog/rzg2l_wdt.c
> > +++ b/drivers/watchdog/rzg2l_wdt.c
> > @@ -123,8 +123,11 @@ static void rzg2l_wdt_init_timeout(struct
> > watchdog_device *wdev)  static int rzg2l_wdt_start(struct watchdog_device *wdev)  {
> >  	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> > +	int ret;
> >
> > -	pm_runtime_get_sync(wdev->parent);
> > +	ret = pm_runtime_resume_and_get(wdev->parent);
> > +	if (ret)
> > +		return ret;
> 
> Checking ret will lead to imbalance. It should be ret < 0 as ret = 1 corresponds to RPM_ACTIVE and
> the API does not call put() when ret = 1; see [1] and [2]
> 
> [1] https://elixir.bootlin.com/linux/v6.10-rc6/source/drivers/base/power/runtime.c#L778
> 
> [2] https://elixir.bootlin.com/linux/v6.10-rc6/source/include/linux/pm_runtime.h#L431

Please ignore me. Sorry for the noise.

the code for pm_runtime_resume_and_get() seems to be correct.
https://elixir.bootlin.com/linux/latest/source/include/linux/pm_runtime.h#L436

Cheers,
Biju
diff mbox series

Patch

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 1741f98ca67c..d87d4f50180c 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -123,8 +123,11 @@  static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev)
 static int rzg2l_wdt_start(struct watchdog_device *wdev)
 {
 	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	int ret;
 
-	pm_runtime_get_sync(wdev->parent);
+	ret = pm_runtime_resume_and_get(wdev->parent);
+	if (ret)
+		return ret;
 
 	/* Initialize time out */
 	rzg2l_wdt_init_timeout(wdev);
@@ -150,6 +153,8 @@  static int rzg2l_wdt_stop(struct watchdog_device *wdev)
 
 static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
 {
+	int ret = 0;
+
 	wdev->timeout = timeout;
 
 	/*
@@ -159,10 +164,10 @@  static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int time
 	 */
 	if (watchdog_active(wdev)) {
 		rzg2l_wdt_stop(wdev);
-		rzg2l_wdt_start(wdev);
+		ret = rzg2l_wdt_start(wdev);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int rzg2l_wdt_restart(struct watchdog_device *wdev,