Re: [PATCH v2] gpio: mockup: Allow probing from device tree

[Vincent Whitchurch]

On Wed, Oct 28, 2020 at 09:25:32PM +0100, Andy Shevchenko wrote:
> On Wed, Oct 28, 2020 at 8:41 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> > On Tue, Oct 27, 2020 at 2:54 PM Vincent Whitchurch
> > > +#ifdef CONFIG_OF
> > > +static const struct of_device_id gpio_mockup_of_match[] = {
> > > +       { .compatible = "gpio-mockup", },
> > > +       {},
> > > +};
> > > +MODULE_DEVICE_TABLE(of, gpio_mockup_of_match);
> > > +#endif
> >
> > You don't need this ifdef - of_match_ptr() will evaluate to NULL if
> > CONFIG_OF is disabled and the compiler will optimize this struct out.
> 
> It's not so. If you drop ugly ifdeffery (and I vote for that, see also
> above) the of_match_ptr() must be dropped as well.  Otherwise the
> compiler will issue the warning. So it is either all or none.

Yes, you're right.  I actually tested a !OF build before but it turns
out that the warning is disabled by default and only enabled with W=1.
I'll fix this and change the header in the next version.  Thank you.