Re: [PATCH] drivers: gpio: use of_match_ptr() and ACPI_PTR() macros

From: Andy Shevchenko
Date: Tue Nov 17 2020 - 11:49:32 EST


On Tue, Nov 17, 2020 at 6:45 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Tue, Nov 17, 2020 at 5:45 PM Enrico Weigelt, metux IT consult
> <info@xxxxxxxxx> wrote:
> >
> > The of_match_ptr(foo) macro evaluates to foo, only if
> > CONFIG_OF is set, otherwise to NULL. Same does ACPI_PTR with
> > CONFIG_ACPI. That's very helpful for drivers that can be used
> > with or without oftree / acpi.
> >
> > Even though most of the drivers touched here probably don't
> > actually need that, it's also nice for consistency to make it
> > the de-facto standard and change all drivers to use the
> > of_match_ptr() and ACPI_PTR() macros.
> >
> > A nice side effect: in some situations, when compiled w/o
> > CONFIG_OF/CONFIG_ACPI, the corresponding match tables could
> > automatically become unreferenced and optimized-away by the
> > compiler, w/o explicitly cluttering the code w/ ifdef's.
>
> NAK.
>
> It prevents using DT-enabled drivers on ACPI based platforms.
>
> +Cc: Jonathan who had done the opposite in the entire IIO subsystem.

And a side note: use of_match_ptr() and ACPI_PTR() in 99% is a mistake.



--
With Best Regards,
Andy Shevchenko