Re: [PATCH v6 4/4] iio: adc: ad799x: use devm_iio_device_register and drop remove()

[Archit Anant]

On Fri, Mar 27, 2026 at 12:45 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxx> wrote:
>
> On Thu, Mar 26, 2026 at 11:35:29PM +0530, Archit Anant wrote:
> > Convert the driver to use the device-managed versions of
> > iio_device_register(), iio_triggered_buffer_setup(), and mutex_init().
> >
> > Use devm_add_action_or_reset() to ensure that the VCC and VREF
> > regulators are disabled safely and in the correct order during
> > driver teardown or probe failure.
> >
> > Because all resources (buffer, regulators, IRQs, IIO device, mutex)
> > are now fully managed by the devm core, the unwinding order is
> > guaranteed to be correct (reverse order of allocation). We can now
> > safely remove all manual error handling goto labels in ad799x_probe()
> > and delete the ad799x_remove() function entirely.
> >
> > This eliminates boilerplate code and prevents potential resource leaks.
>
> ...
>
> > -     mutex_init(&st->lock);
> > -
> > -     ret = iio_device_register(indio_dev);
> > +     ret = devm_mutex_init(dev, &st->lock);
>
> Looking at how far from the start of probe this is done, it's prone to problems.
> What we need is to decouple this change and move mutex to be enabled before any
> interrupts or other async events may happen.
>

I understand how this can cause issues; I'll move the mutex lock up in
probe before any interrupts or other async events can occur and send a
new revision.

> >       if (ret)
> > -             goto error_cleanup_ring;
> > -
> > -     return 0;
> > -
> > -error_cleanup_ring:
> > -     iio_triggered_buffer_cleanup(indio_dev);
> > -error_disable_vref:
> > -     if (st->vref)
> > -             regulator_disable(st->vref);
> > -error_disable_reg:
> > -     regulator_disable(st->reg);
> > -
> > -     return ret;
> > -}
>
>
> --
> With Best Regards,
> Andy Shevchenko
>
>


-- 
Sincerely,
Archit Anant