Re: [PATCH] thermal: devfreq_cooling: Fix kernel-doc

[Nathan Chancellor]

On 6/8/2021 11:39 AM, Nick Desaulniers wrote:
> On Tue, Jun 8, 2021 at 2:46 AM Yang Li <yang.lee@xxxxxxxxxxxxxxxxx> wrote:
> > Fix function name in devfreq_cooling.c kernel-doc comment
> > to remove a warning found by clang(make W=1 LLVM=1).
> >
> > drivers/thermal/devfreq_cooling.c:479: warning: expecting prototype for
> > devfreq_cooling_em_register_power(). Prototype was for
> > devfreq_cooling_em_register() instead.
> >
> > Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
> > Signed-off-by: Yang Li <yang.lee@xxxxxxxxxxxxxxxxx>
>
> That compiler warning doesn't come from kernel-doc.  Your diff looks
> good (the comment was wrong), but the commit message is curious.

No, this is indeed kernel-doc complaining. Clang should not even be 
mentioned in the commit message:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/kernel-doc?h=v5.13-rc5#n1228

The warning could probably be improved to say "definition" instead of 
"prototype" in certain cases but *shrugs*.

This warning is similar to -Wmissing-prototypes from clang but refers to 
the fact that the comment claims it is documenting one function but it 
is really documenting another.

Cheers,
Nathan

> Usually that warning is from when the function prototype does not
> exist for a function with extern linkage.  It looks like that's always
> provided though in include/linux/devfreq_cooling.h.  Can you share a
> link to the original report?
>
> > ---
> >   drivers/thermal/devfreq_cooling.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
> > index 3a788ac..5a86cff 100644
> > --- a/drivers/thermal/devfreq_cooling.c
> > +++ b/drivers/thermal/devfreq_cooling.c
> > @@ -458,7 +458,7 @@ struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
> >   EXPORT_SYMBOL_GPL(devfreq_cooling_register);
> >
> >   /**
> > - * devfreq_cooling_em_register_power() - Register devfreq cooling device with
> > + * devfreq_cooling_em_register() - Register devfreq cooling device with
> >    *             power information and automatically register Energy Model (EM)
> >    * @df:                Pointer to devfreq device.
> >    * @dfc_power: Pointer to devfreq_cooling_power.
> > --
> > 1.8.3.1