Re: [PATCH] eeprom: at24: use of_match_ptr()

From: Bartosz Golaszewski
Date: Wed Nov 22 2023 - 12:26:44 EST


On Wed, Nov 22, 2023 at 6:14 PM Peter Rosin <peda@xxxxxxxxxx> wrote:
>
>
> 2023-11-22 at 17:57, Bartosz Golaszewski wrote:
> > On Wed, 22 Nov 2023 at 17:41, Peter Rosin <peda@xxxxxxxxxx> wrote:
> >>
> >> Hi!
> >>
> >> 2023-11-22 at 16:59, Bartosz Golaszewski wrote:
> >>> - .of_match_table = at24_of_match,
> >>> + .of_match_table = of_match_ptr(at24_of_match),
> >>
> >> If you do that, you will need to also add #ifdef CONFIG_OF around the
> >> at24_of_match definition, of you'll trigger a warning about an unused
> >> const variable (for some configs). I think.
> >>
> >> Cheers,
> >> Peter
> >
> > Nope, no warnings even with W=2. This is true for unused functions but
> > unused data structures are just silently removed.
>
> Then I wonder what the difference is from the following?
>
> https://lore.kernel.org/all/202311161306.opyfcoCY-lkp@xxxxxxxxx/T/#m3a33dc4c3221ae167563bcff70757af776cf07b1
>
> It sure looks like the exact same pattern to me.
> I.e. a static const struct of_device_id paired with of_match_ptr().
>
> CHeers,
> Peter

Ah, we need __maybe_unused here.

Bart