Thread (4 messages) 4 messages, 3 authors, 2016-11-30

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

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2016-11-29 17:35:06
Also in: linux-media

Hi Sakari,

Thank you for the patch.

On Tuesday 29 Nov 2016 19:28:53 Sakari Ailus wrote:
quoted hunk ↗ jump to hunk
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.
quoted hunk ↗ jump to hunk
@@ -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
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