Re: [PATCH 3/8] iio: magnetometer: ak8975: switch to using managed resources

[Joshua Crofts]

On Sat, 9 May 2026 at 19:15, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Sat, May 09, 2026 at 10:03:38AM +0100, Nuno Sá wrote:
> > On Thu, 2026-05-07 at 16:35 +0200, Joshua Crofts via B4 Relay wrote:
>
> > > Switch the driver to use managed resources (devm_*) which simplifier
> > > error handling and allows removing ak8975_remove() method from
> > > the driver.
> > >
> > > Note, on error path we now also set mode to POWER_DOWN state which is
> > > fine. Even if the device is in that mode, there is no problem to set
> > > that mode again, it should be no-op.
> > >
> > > Additionally, remove any pm_runtime_get/put*() function calls that
> > > dummy cycled the counter to autosuspend the device.
>
> ...
>
> > Maybe it would make sense to move this before devm_iio_device_register(). At the
> > point we register the device, userspace can start to interact with the device where
> > we have pm calls? Not that it is a problem (I think) but makes sense to me to enable
> > PM before exposing the device.
>
> When you called devm_iio_device_register(), it's already user space interaction
> there, so device has to be prepared for that. Do we guarantee that device is
> power enabled at that point?

Okay, I'm all for moving devm_pm_runtime_enable() before
devm_iio_device_register(),
it makes sense to set up pm_runtime before opening the driver to
userspace. I'll push
out a (hopefully final) fix today so we can wrap up this series.

-- 
Kind regards

CJD