[PATCH v2 0/2] smiapp fix for w/o CONFIG_PM, compiler warnings

[PATCH v2 0/2] smiapp fix for w/o CONFIG_PM, compiler warnings

[Sakari Ailus]

Hi,

The two patches fix the PM / compiler warning issues Arnd found in the
smiapp driver.

since v1:

- Use IS_ENABLED() instead of preprocessor macros.

- Add another patch to fix compiler warnings.

-- 
Kind regards,
Sakari

[PATCH v2 1/2] smiapp: Implement power-on and power-off sequences without runtime PM

[Sakari Ailus]

Power on the sensor when the module is loaded and power it off when it is
removed.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/i2c/smiapp/smiapp-core.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
index 59872b3..b20886f 100644
--- a/drivers/media/i2c/smiapp/smiapp-core.c
+++ b/drivers/media/i2c/smiapp/smiapp-core.c
@@ -2741,8 +2741,6 @@ static const struct v4l2_subdev_internal_ops smiapp_internal_ops = {
  * I2C Driver
  */
 
-#ifdef CONFIG_PM
-
 static int smiapp_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -2783,13 +2781,6 @@ static int smiapp_resume(struct device *dev)
 	return rval;
 }
 
-#else
-
-#define smiapp_suspend	NULL
-#define smiapp_resume	NULL
-
-#endif /* CONFIG_PM */
-
 static struct smiapp_hwconfig *smiapp_get_hwconfig(struct device *dev)
 {
 	struct smiapp_hwconfig *hwcfg;
@@ -2915,7 +2906,10 @@ static int smiapp_probe(struct i2c_client *client,
 
 	pm_runtime_enable(&client->dev);
 
-	rval = pm_runtime_get_sync(&client->dev);
+	if (IS_ENABLED(CONFIG_PM))
+		rval = pm_runtime_get_sync(&client->dev);
+	else
+		rval = smiapp_power_on(&client->dev);
 	if (rval < 0) {
 		rval = -ENODEV;
 		goto out_power_off;
@@ -3113,7 +3107,10 @@ static int smiapp_probe(struct i2c_client *client,
 	smiapp_cleanup(sensor);
 
 out_power_off:
-	pm_runtime_put(&client->dev);
+	if (IS_ENABLED(CONFIG_PM))
+		pm_runtime_put(&client->dev);
+	else
+		smiapp_power_off(&client->dev);
 	pm_runtime_disable(&client->dev);
 
 	return rval;
@@ -3127,7 +3124,10 @@ static int smiapp_remove(struct i2c_client *client)
 
 	v4l2_async_unregister_subdev(subdev);
 
-	pm_runtime_suspend(&client->dev);
+	if (IS_ENABLED(CONFIG_PM))
+		pm_runtime_suspend(&client->dev);
+	else
+		smiapp_power_off(&client->dev);
 	pm_runtime_disable(&client->dev);
 
 	for (i = 0; i < sensor->ssds_used; i++) {
-- 
2.1.4

[PATCH v2 2/2] smiapp: Make suspend and resume functions __maybe_unused

[Sakari Ailus]

The smiapp_suspend() and smiapp_resume() functions will end up being unused
if CONFIG_PM is enabled but CONFIG_PM_SLEEP is disabled, causing a
compiler warning from both of the function definitions. Fix this by
marking the functions with __maybe_unused.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/i2c/smiapp/smiapp-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
index b20886f..ab48a85 100644
--- a/drivers/media/i2c/smiapp/smiapp-core.c
+++ b/drivers/media/i2c/smiapp/smiapp-core.c
@@ -2741,7 +2741,7 @@ static const struct v4l2_subdev_internal_ops smiapp_internal_ops = {
  * I2C Driver
  */
 
-static int smiapp_suspend(struct device *dev)
+static int __maybe_unused smiapp_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
@@ -2766,7 +2766,7 @@ static int smiapp_suspend(struct device *dev)
 	return 0;
 }
 
-static int smiapp_resume(struct device *dev)
+static int __maybe_unused smiapp_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
-- 
2.1.4

[PATCH v2.1 1/2] smiapp: Implement power-on and power-off sequences without runtime PM

[Sakari Ailus]

Power on the sensor when the module is loaded and power it off when it is
removed.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
Hi Alan and Laurent,

I hope this should be good then. I'm only enabling runtime PM at the end
of probe() when all is well, which reduces need for error handling.

Regards,
Sakari

 drivers/media/i2c/smiapp/smiapp-core.c | 28 +++++++++-------------------
 1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
index 59872b3..683a3e0 100644
--- a/drivers/media/i2c/smiapp/smiapp-core.c
+++ b/drivers/media/i2c/smiapp/smiapp-core.c
@@ -2741,8 +2741,6 @@ static const struct v4l2_subdev_internal_ops smiapp_internal_ops = {
  * I2C Driver
  */
 
-#ifdef CONFIG_PM
-
 static int smiapp_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -2783,13 +2781,6 @@ static int smiapp_resume(struct device *dev)
 	return rval;
 }
 
-#else
-
-#define smiapp_suspend	NULL
-#define smiapp_resume	NULL
-
-#endif /* CONFIG_PM */
-
 static struct smiapp_hwconfig *smiapp_get_hwconfig(struct device *dev)
 {
 	struct smiapp_hwconfig *hwcfg;
@@ -2913,13 +2904,9 @@ static int smiapp_probe(struct i2c_client *client,
 	if (IS_ERR(sensor->xshutdown))
 		return PTR_ERR(sensor->xshutdown);
 
-	pm_runtime_enable(&client->dev);
-
-	rval = pm_runtime_get_sync(&client->dev);
-	if (rval < 0) {
-		rval = -ENODEV;
-		goto out_power_off;
-	}
+	rval = smiapp_power_on(&client->dev);
+	if (rval < 0)
+		return rval;
 
 	rval = smiapp_identify_module(sensor);
 	if (rval) {
@@ -3100,6 +3087,9 @@ static int smiapp_probe(struct i2c_client *client,
 	if (rval < 0)
 		goto out_media_entity_cleanup;
 
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_get_noresume(&client->dev);
+	pm_runtime_enable(&client->dev);
 	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
 	pm_runtime_use_autosuspend(&client->dev);
 	pm_runtime_put_autosuspend(&client->dev);
@@ -3113,8 +3103,7 @@ static int smiapp_probe(struct i2c_client *client,
 	smiapp_cleanup(sensor);
 
 out_power_off:
-	pm_runtime_put(&client->dev);
-	pm_runtime_disable(&client->dev);
+	smiapp_power_off(&client->dev);
 
 	return rval;
 }
@@ -3127,8 +3116,9 @@ static int smiapp_remove(struct i2c_client *client)
 
 	v4l2_async_unregister_subdev(subdev);
 
-	pm_runtime_suspend(&client->dev);
 	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	smiapp_power_off(&client->dev);
 
 	for (i = 0; i < sensor->ssds_used; i++) {
 		v4l2_device_unregister_subdev(&sensor->ssds[i].sd);
-- 
2.1.4

Re: [PATCH v2.1 1/2] smiapp: Implement power-on and power-off sequences without runtime PM

[Laurent Pinchart]

Hi Sakari,

Thank you for the patch.

On Tuesday 29 Nov 2016 19:28:53 Sakari Ailus wrote:
> Power on the sensor when the module is loaded and power it off when it is
> removed.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
> Hi Alan and Laurent,
> 
> I hope this should be good then. I'm only enabling runtime PM at the end
> of probe() when all is well, which reduces need for error handling.
> 
> Regards,
> Sakari
> 
>  drivers/media/i2c/smiapp/smiapp-core.c | 28 +++++++++-------------------
>  1 file changed, 9 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/i2c/smiapp/smiapp-core.c
> b/drivers/media/i2c/smiapp/smiapp-core.c index 59872b3..683a3e0 100644
> --- a/drivers/media/i2c/smiapp/smiapp-core.c
> +++ b/drivers/media/i2c/smiapp/smiapp-core.c
> @@ -2741,8 +2741,6 @@ static const struct v4l2_subdev_internal_ops
> smiapp_internal_ops = { * I2C Driver
>   */
> 
> -#ifdef CONFIG_PM
> -
>  static int smiapp_suspend(struct device *dev)
>  {
>  	struct i2c_client *client = to_i2c_client(dev);
> @@ -2783,13 +2781,6 @@ static int smiapp_resume(struct device *dev)
>  	return rval;
>  }
> 
> -#else
> -
> -#define smiapp_suspend	NULL
> -#define smiapp_resume	NULL
> -
> -#endif /* CONFIG_PM */
> -
>  static struct smiapp_hwconfig *smiapp_get_hwconfig(struct device *dev)
>  {
>  	struct smiapp_hwconfig *hwcfg;
> @@ -2913,13 +2904,9 @@ static int smiapp_probe(struct i2c_client *client,
>  	if (IS_ERR(sensor->xshutdown))
>  		return PTR_ERR(sensor->xshutdown);
> 
> -	pm_runtime_enable(&client->dev);
> -
> -	rval = pm_runtime_get_sync(&client->dev);
> -	if (rval < 0) {
> -		rval = -ENODEV;
> -		goto out_power_off;
> -	}
> +	rval = smiapp_power_on(&client->dev);
> +	if (rval < 0)
> +		return rval;
> 
>  	rval = smiapp_identify_module(sensor);
>  	if (rval) {
> @@ -3100,6 +3087,9 @@ static int smiapp_probe(struct i2c_client *client,
>  	if (rval < 0)
>  		goto out_media_entity_cleanup;
> 
> +	pm_runtime_set_active(&client->dev);
> +	pm_runtime_get_noresume(&client->dev);
> +	pm_runtime_enable(&client->dev);
>  	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
>  	pm_runtime_use_autosuspend(&client->dev);
>  	pm_runtime_put_autosuspend(&client->dev);

This looks better to me, although these 6 lines really call for a new helper 
function.

However, I still believe a helper that calls the runtime PM handlers directly 
when CONFIG_PM=n and rely on runtime PM when CONFIG_PM=y would be the cleanest 
solution from a driver point of view.

> @@ -3113,8 +3103,7 @@ static int smiapp_probe(struct i2c_client *client,
>  	smiapp_cleanup(sensor);
> 
>  out_power_off:
> -	pm_runtime_put(&client->dev);
> -	pm_runtime_disable(&client->dev);
> +	smiapp_power_off(&client->dev);
> 
>  	return rval;
>  }
> @@ -3127,8 +3116,9 @@ static int smiapp_remove(struct i2c_client *client)
> 
>  	v4l2_async_unregister_subdev(subdev);
> 
> -	pm_runtime_suspend(&client->dev);
>  	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	smiapp_power_off(&client->dev);

The device could be powered off already.

> 
>  	for (i = 0; i < sensor->ssds_used; i++) {
>  		v4l2_device_unregister_subdev(&sensor->ssds[i].sd);

-- 
Regards,

Laurent Pinchart

Re: [PATCH v2.1 1/2] smiapp: Implement power-on and power-off sequences without runtime PM

[Sakari Ailus]

Hi Laurent,

On Tue, Nov 29, 2016 at 07:35:17PM +0200, Laurent Pinchart wrote:
> Hi Sakari,
> 
> Thank you for the patch.
> 
> On Tuesday 29 Nov 2016 19:28:53 Sakari Ailus wrote:
> > Power on the sensor when the module is loaded and power it off when it is
> > removed.
> > 
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> > Hi Alan and Laurent,
> > 
> > I hope this should be good then. I'm only enabling runtime PM at the end
> > of probe() when all is well, which reduces need for error handling.
> > 
> > Regards,
> > Sakari
> > 
> >  drivers/media/i2c/smiapp/smiapp-core.c | 28 +++++++++-------------------
> >  1 file changed, 9 insertions(+), 19 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/smiapp/smiapp-core.c
> > b/drivers/media/i2c/smiapp/smiapp-core.c index 59872b3..683a3e0 100644
> > --- a/drivers/media/i2c/smiapp/smiapp-core.c
> > +++ b/drivers/media/i2c/smiapp/smiapp-core.c
> > @@ -2741,8 +2741,6 @@ static const struct v4l2_subdev_internal_ops
> > smiapp_internal_ops = { * I2C Driver
> >   */
> > 
> > -#ifdef CONFIG_PM
> > -
> >  static int smiapp_suspend(struct device *dev)
> >  {
> >  	struct i2c_client *client = to_i2c_client(dev);
> > @@ -2783,13 +2781,6 @@ static int smiapp_resume(struct device *dev)
> >  	return rval;
> >  }
> > 
> > -#else
> > -
> > -#define smiapp_suspend	NULL
> > -#define smiapp_resume	NULL
> > -
> > -#endif /* CONFIG_PM */
> > -
> >  static struct smiapp_hwconfig *smiapp_get_hwconfig(struct device *dev)
> >  {
> >  	struct smiapp_hwconfig *hwcfg;
> > @@ -2913,13 +2904,9 @@ static int smiapp_probe(struct i2c_client *client,
> >  	if (IS_ERR(sensor->xshutdown))
> >  		return PTR_ERR(sensor->xshutdown);
> > 
> > -	pm_runtime_enable(&client->dev);
> > -
> > -	rval = pm_runtime_get_sync(&client->dev);
> > -	if (rval < 0) {
> > -		rval = -ENODEV;
> > -		goto out_power_off;
> > -	}
> > +	rval = smiapp_power_on(&client->dev);
> > +	if (rval < 0)
> > +		return rval;
> > 
> >  	rval = smiapp_identify_module(sensor);
> >  	if (rval) {
> > @@ -3100,6 +3087,9 @@ static int smiapp_probe(struct i2c_client *client,
> >  	if (rval < 0)
> >  		goto out_media_entity_cleanup;
> > 
> > +	pm_runtime_set_active(&client->dev);
> > +	pm_runtime_get_noresume(&client->dev);
> > +	pm_runtime_enable(&client->dev);
> >  	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> >  	pm_runtime_use_autosuspend(&client->dev);
> >  	pm_runtime_put_autosuspend(&client->dev);
> 
> This looks better to me, although these 6 lines really call for a new helper 
> function.

They're somewhat unrelated, especially the autosuspend part. Few drivers use
it.

> 
> However, I still believe a helper that calls the runtime PM handlers directly 
> when CONFIG_PM=n and rely on runtime PM when CONFIG_PM=y would be the cleanest 
> solution from a driver point of view.
> 
> > @@ -3113,8 +3103,7 @@ static int smiapp_probe(struct i2c_client *client,
> >  	smiapp_cleanup(sensor);
> > 
> >  out_power_off:
> > -	pm_runtime_put(&client->dev);
> > -	pm_runtime_disable(&client->dev);
> > +	smiapp_power_off(&client->dev);
> > 
> >  	return rval;
> >  }
> > @@ -3127,8 +3116,9 @@ static int smiapp_remove(struct i2c_client *client)
> > 
> >  	v4l2_async_unregister_subdev(subdev);
> > 
> > -	pm_runtime_suspend(&client->dev);
> >  	pm_runtime_disable(&client->dev);
> > +	pm_runtime_set_suspended(&client->dev);
> > +	smiapp_power_off(&client->dev);
> 
> The device could be powered off already.

Good point.

The autosuspend must be explicitly disabled as well which wasn't previously
done. I'll add another patch for that.

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

[PATCH v2.2 1/2] smiapp: Implement power-on and power-off sequences without runtime PM

[Sakari Ailus]

Power on the sensor when the module is loaded and power it off when it is
removed.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v2.1:

- Power off conditionally, i.e. only if the device was powered.
  pm_runtime_status_suspended() returns false if CONFIG_PM is not set.

 drivers/media/i2c/smiapp/smiapp-core.c | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
index 59872b3..620f8ce 100644
--- a/drivers/media/i2c/smiapp/smiapp-core.c
+++ b/drivers/media/i2c/smiapp/smiapp-core.c
@@ -2741,8 +2741,6 @@ static const struct v4l2_subdev_internal_ops smiapp_internal_ops = {
  * I2C Driver
  */
 
-#ifdef CONFIG_PM
-
 static int smiapp_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -2783,13 +2781,6 @@ static int smiapp_resume(struct device *dev)
 	return rval;
 }
 
-#else
-
-#define smiapp_suspend	NULL
-#define smiapp_resume	NULL
-
-#endif /* CONFIG_PM */
-
 static struct smiapp_hwconfig *smiapp_get_hwconfig(struct device *dev)
 {
 	struct smiapp_hwconfig *hwcfg;
@@ -2913,13 +2904,9 @@ static int smiapp_probe(struct i2c_client *client,
 	if (IS_ERR(sensor->xshutdown))
 		return PTR_ERR(sensor->xshutdown);
 
-	pm_runtime_enable(&client->dev);
-
-	rval = pm_runtime_get_sync(&client->dev);
-	if (rval < 0) {
-		rval = -ENODEV;
-		goto out_power_off;
-	}
+	rval = smiapp_power_on(&client->dev);
+	if (rval < 0)
+		return rval;
 
 	rval = smiapp_identify_module(sensor);
 	if (rval) {
@@ -3100,6 +3087,9 @@ static int smiapp_probe(struct i2c_client *client,
 	if (rval < 0)
 		goto out_media_entity_cleanup;
 
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_get_noresume(&client->dev);
+	pm_runtime_enable(&client->dev);
 	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
 	pm_runtime_use_autosuspend(&client->dev);
 	pm_runtime_put_autosuspend(&client->dev);
@@ -3113,8 +3103,7 @@ static int smiapp_probe(struct i2c_client *client,
 	smiapp_cleanup(sensor);
 
 out_power_off:
-	pm_runtime_put(&client->dev);
-	pm_runtime_disable(&client->dev);
+	smiapp_power_off(&client->dev);
 
 	return rval;
 }
@@ -3127,8 +3116,10 @@ static int smiapp_remove(struct i2c_client *client)
 
 	v4l2_async_unregister_subdev(subdev);
 
-	pm_runtime_suspend(&client->dev);
 	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_status_suspended(&client->dev))
+		smiapp_power_off(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
 
 	for (i = 0; i < sensor->ssds_used; i++) {
 		v4l2_device_unregister_subdev(&sensor->ssds[i].sd);
-- 
2.1.4