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:

quoted

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.

quoted

@@ -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