Re: [PATCH v3 1/5] hwmon: (core) Inherit power properties to hdev

linux
2018-10-25T00:13:03Z

Quoting Nicolin Chen <nicoleotsuka@gmail.com>:

> The new hdev is a child device related to the original parent
> hwmon driver and its device. However, it doesn't support the
> power features, typically being defined in the parent driver.
>
> So this patch inherits three necessary power properties from
> the parent dev to hdev: power, pm_domain and driver pointers.
>
> Note that the dev->driver pointer is the place that contains
> a dev_pm_ops pointer defined in the parent device driver and
> the pm runtime core also checks this pointer:
> if (!cb && dev->driver && dev->driver->pm)
>
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> ---
> Changelog
> v2->v3:
> * N/A
> v1->v2:
> * Added device pointers
>
> drivers/hwmon/hwmon.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index 975c95169884..14cfab64649f 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -625,7 +625,12 @@ __hwmon_device_register(struct device *dev,
> const char *name, void *drvdata,
> hwdev->name = name;
> hdev->class = &hwmon_class;
> hdev->parent = dev;
> - hdev->of_node = dev ? dev->of_node : NULL;
> + if (dev) {
> + hdev->driver = dev->driver;
> + hdev->power = dev->power;
> + hdev->pm_domain = dev->pm_domain;
> + hdev->of_node = dev->of_node;
> + }

We'l need to dig into this more; I suspect it may be inappropriate to do this.
With this change, every hwmon driver supporting (runtime ?) suspend/resume
will have the problem worked around in #5, and that just seems wrong.

Guenter

> hwdev->chip = chip;
> dev_set_drvdata(hdev, drvdata);
> dev_set_name(hdev, HWMON_ID_FORMAT, id);
> --
> 2.17.1