Re: [PATCH v1 1/3] hwmon: (pwm-fan) Make use of device properties

From: Andy Shevchenko
Date: Fri Aug 19 2022 - 05:58:58 EST


On Fri, Aug 19, 2022 at 12:56 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Fri, Aug 19, 2022 at 2:41 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > On Sat, Aug 06, 2022 at 06:25:15PM +0300, Andy Shevchenko wrote:
> > > Convert the module to be property provider agnostic and allow
> > > it to be used on non-OF platforms.
> > >
> > > Add mod_devicetable.h include.
> > >
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > > Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> >
> > I had another look at this patch. A substantial part of the changes
> > is because device properties don't support of_property_read_u32_index(),
> > reworking the code to use device_property_read_u32_array() instead.
> > Sorry, I don't like it, it results in a substantial number of unnecessary
> > changes. Device properties should support the equivalent of
> > of_property_read_u32_index() instead to simplify conversions.
>
> Not all (device property) providers can have such API available. Are
> you suggesting to
> a) alloc memory for entire array;
> b) cache one for a given index;
> c) free a memory;
> d) loop as many times as index op is called.
>
> Sorry, this is way too far and non-optimal in comparison to the
> substantial number of unnecessary changes (two or three small
> refactorings?).
>
> Another way is to provide a pwm-fan-acpi, which will be the copy of
> the driver after this patch is applied. I don't think it's a very
> bright idea either.

That said, I will split a change for PWM cleaning up series and leave
the rest on the hwmon maintainers to reconsider.

--
With Best Regards,
Andy Shevchenko