Re: [PATCH] ACPI: processor: Fix function defined but not used warning

["lihuisong (C)" <lihuisong@xxxxxxxxxx>]

在 2025/9/4 23:23, Rafael J. Wysocki 写道:
> On Thu, Sep 4, 2025 at 2:11 PM Huisong Li <lihuisong@xxxxxxxxxx> wrote:
> > If CONFIG_ACPI_PROCESSOR=n and CONFIG_ACPI_PROCESSOR_IDLE=n, we may
> > encounter some compling warnings as the following link said.
> > So remove these empty function definition because they are just used
> > in processor_driver.c and if CONFIG_ACPI_PROCESSOR is selected and
> > CONFIG_ACPI_PROCESSOR_IDLE also be selected automatically.
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202508300519.tZQHY6HA-lkp@xxxxxxxxx/
> >
> > Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> > ---
> >   include/acpi/processor.h | 34 +++-------------------------------
> >   1 file changed, 3 insertions(+), 31 deletions(-)
> >
> > diff --git a/include/acpi/processor.h b/include/acpi/processor.h
> > index 360b673f05e5..a4e1081fd0da 100644
> > --- a/include/acpi/processor.h
> > +++ b/include/acpi/processor.h
> > @@ -417,40 +417,17 @@ static inline void acpi_processor_throttling_init(void) {}
> >   #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
> >
> >   /* in processor_idle.c */
> > -extern struct cpuidle_driver acpi_idle_driver;
> >   #ifdef CONFIG_ACPI_PROCESSOR_IDLE
> > +extern struct cpuidle_driver acpi_idle_driver;
> Are the changes above related to the warning?  If not, maybe move them
> to a separate patch?
Ok, will do it in a separate patch.
> >   int acpi_processor_power_init(struct acpi_processor *pr);
> >   int acpi_processor_power_exit(struct acpi_processor *pr);
> >   int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
> >   int acpi_processor_hotplug(struct acpi_processor *pr);
> >   void acpi_processor_register_idle_driver(void);
> >   void acpi_processor_unregister_idle_driver(void);
> > -#else
> > -static inline int acpi_processor_power_init(struct acpi_processor *pr)
> > -{
> > -       return -ENODEV;
> > -}
> > -
> > -static inline int acpi_processor_power_exit(struct acpi_processor *pr)
> > -{
> > -       return -ENODEV;
> > -}
> > -
> > -static inline int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
> > -{
> > -       return -ENODEV;
> > -}
> >
> > -static inline int acpi_processor_hotplug(struct acpi_processor *pr)
> > -{
> > -       return -ENODEV;
> > -}
> > -static inline void acpi_processor_register_idle_driver(void)
> > -{
> > -}
> > -static inline void acpi_processor_unregister_idle_driver(void)
> > -{
> > -}
> > +extern int acpi_processor_ffh_lpi_probe(unsigned int cpu);
> > +extern int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi);
> Please remove the "extern" from these declarations.
Ack
> >   #endif /* CONFIG_ACPI_PROCESSOR_IDLE */
> >
> >   /* in processor_thermal.c */
> > @@ -473,11 +450,6 @@ static inline void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
> >   }
> >   #endif /* CONFIG_CPU_FREQ */
> >
> > -#ifdef CONFIG_ACPI_PROCESSOR_IDLE
> > -extern int acpi_processor_ffh_lpi_probe(unsigned int cpu);
> > -extern int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi);
> > -#endif
> > -
> >   void acpi_processor_init_invariance_cppc(void);
> >
> >   #endif
> > --