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

From: Andy Shevchenko
Date: Wed Nov 18 2020 - 04:56:29 EST


On Wed, Nov 18, 2020 at 11:54 AM Uwe Kleine-König
<u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> On Tue, Nov 17, 2020 at 06:45:37PM +0200, Andy Shevchenko 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.
>
> So a system without CONFIG_OF might still make use of .of_match_table?

Yep!

> If so: TIL ...

--
With Best Regards,
Andy Shevchenko