Re: [PATCH v2 2/2] rust: regulator: add devm_enable and devm_enable_optional

[Boqun Feng <boqun.feng@gmail.com>]

On Tue, Sep 09, 2025 at 05:58:34PM +0200, Miguel Ojeda wrote:
> On Tue, Sep 9, 2025 at 5:38 PM Boqun Feng <boqun.feng@gmail.com> wrote:
> >
> > Well, then the question is why we want to compiler regulator.rs if
> > CONFIG_REGULATOR=n? Shouldn't we do:
> >
> > #[cfg(CONFIG_REGULATOR)]
> > pub mod regulator
> >
> > in rust/kernel/lib.rs?
> 
> It depends on what the C API does -- if the C API is supposed to
> "always work" (even if it is no-op or if it returns errors) even when
> disabled (so that callers are easier), then we likely need to
> replicate that on our side.
> 

While I don't disagree with the rule in general, but I do want to say
the cost is the binary size (at least without inlining helpers), so I
think we are allowed to apply this rule case by case, i.e. even if a C
API is supposed to "always work" but Rust can avoid exposing the API at
some configurations.

I of course don't have a strong opinion on what the regulator subsystem
should do ;-)

Regards,
Boqun

> We had a similar discussion for DebugFS.
> 
> Cheers,
> Miguel