Re: [PATCH] iio: light: vcnl4000: Don't create sysfs PM nodes for child

[Sudeep Holla <sudeep.holla@arm.com>]

On Sun, Nov 06, 2022 at 03:23:07PM +0000, Jonathan Cameron wrote:
> On Tue, 1 Nov 2022 13:21:51 +0100
> Mårten Lindahl <marten.lindahl@axis.com> wrote:
> 
> > PM runtime is enabled for the parent i2c device, but it is disabled for
> > the iio child device and remains so in this driver. But as the child
> > sysfs PM directory is created by default by iio_device_register =>
> > cdev_device_add => dpm_sysfs_add it doesn't bring any value exposing it
> > since it won't give any usable data for the user.
> > 
> > Tell dpm_sysfs to not create the PM directory for the iio device.
> > 
> > Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
> 
> Ah this one..  +CC Sudeep who I am sure has considered such changes in other
> similar cases (he did the original ones that mean this infastructure exists).
>

Yes it was added for cache devices which are child devices of CPU devices via
Commit 85945c28b5a8 ("PM / core: Add support to skip power management in device/driver model")

Since CPU and its children are power managed quite differently(via cpuidle
or cpu hotplug), the new API(device_set_pm_not_required) fits the usecase
there well. I am not sure about this IIO usecase.

-- 
Regards,
Sudeep