Hi Hyungwoo,
On Thu, Jun 01, 2017 at 03:45:16PM -0700, Hyungwoo Yang wrote:
...
> +static int ov13858_probe(struct i2c_client *client,
> + const struct i2c_device_id *devid)
> +{
> + struct ov13858 *ov13858;
> + int ret;
> +
> + ov13858 = devm_kzalloc(&client->dev, sizeof(*ov13858), GFP_KERNEL);
> + if (!ov13858)
> + return -ENOMEM;
> +
> + /* Initialize subdev */
> + v4l2_i2c_subdev_init(&ov13858->sd, client, &ov13858_subdev_ops);
> +
> + /*
> + * Enable runtime PM.
> + * The sensor is already powered on ACPI domain PM
> + */
> + pm_runtime_get_noresume(&client->dev);
> + pm_runtime_set_active(&client->dev);
> + pm_runtime_enable(&client->dev);
As you already have in comments, the device is already powered on in an ACPI
based system. pm_runtime_get_noresume() prevents powering the device off
during probe after runtime PM is enabled.
It'd be better to also move the calls to pm_runtime_set_active() and
pm_runtime_enable() just before returning 0. This way you can get rid of
extra error handling you'd otherwise need to do: once you call
pm_runtime_get_noresume(), you need to call pm_runtime_put() or one of its
variants as well.
> +
> + /* Check module identity */
> + ret = ov13858_identify_module(ov13858);
> + if (ret) {
> + dev_err(&client->dev, "failed to find sensor: %d\n", ret);
> + return ret;
> + }
> +
> + /* Set default mode to max resolution */
> + ov13858->cur_mode = &supported_modes[0];
> +
> + ret = ov13858_init_controls(ov13858);
> + if (ret)
> + return ret;
> +
> + /* Initialize subdev */
> + ov13858->sd.internal_ops = &ov13858_internal_ops;
> + ov13858->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> + ov13858->sd.entity.ops = &ov13858_subdev_entity_ops;
> + ov13858->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +
> + /* Initialize source pad */
> + ov13858->pad.flags = MEDIA_PAD_FL_SOURCE;
> + ret = media_entity_pads_init(&ov13858->sd.entity, 1, &ov13858->pad);
> + if (ret) {
> + dev_err(&client->dev, "%s failed:%d\n", __func__, ret);
> + goto error_handler_free;
> + }
> +
> + ret = v4l2_async_register_subdev(&ov13858->sd);
> + if (ret < 0)
> + goto error_media_entity;
> +
> + /* Turn off */
> + pm_runtime_put(&client->dev);
> +
> + return 0;
> +
> +error_media_entity:
> + media_entity_cleanup(&ov13858->sd.entity);
> +
> +error_handler_free:
> + ov13858_free_controls(ov13858);
> + dev_err(&client->dev, "%s failed:%d\n", __func__, ret);
> +
> + return ret;
> +}
--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
