Re: [PATCH] acpi: fix pwr_btn_event_pending build error

Rafael J. Wysocki
2012-07-23T18:52:58Z

On Sunday, July 22, 2012, Paul E. McKenney wrote:
> On Sun, Jul 22, 2012 at 07:40:51PM +0200, Rafael J. Wysocki wrote:
> > On Sunday, July 22, 2012, Paul E. McKenney wrote:
> > > On Sun, Jul 22, 2012 at 03:08:40AM +0300, Kirill A. Shutemov wrote:
> > > > On Sat, Jul 21, 2012 at 04:37:14PM -0700, Paul E. McKenney wrote:
> > > > > On Sun, Jul 22, 2012 at 12:52:43AM +0300, Kirill A. Shutemov wrote:
> > > > > > On Sat, Jul 21, 2012 at 02:41:56PM -0700, Paul E. McKenney wrote:
> > > > > > > Hello!
> > > > > > >
> > > > > > > A recent build for KVM on x86 resulted in the following build error:
> > > > > > >
> > > > > > > drivers/acpi/sleep.c:60:13: warning: ‘pwr_btn_event_pending’ defined but not
> > > > > > > +used [-Wunused-variable]
> > > > > > >
> > > > > > > This patch silences this error.
> > > > > > >
> > > > > > > Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
> > > > > > >
> > > > > > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> > > > > > > index 8856102..18347aa 100644
> > > > > > > --- a/drivers/acpi/sleep.c
> > > > > > > +++ b/drivers/acpi/sleep.c
> > > > > > > @@ -57,7 +57,9 @@ MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
> > > > > > > MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
> > > > > > >
> > > > > > > static u8 sleep_states[ACPI_S_STATE_COUNT];
> > > > > > > +#ifdef CONFIG_ACPI_SLEEP
> > > > > > > static bool pwr_btn_event_pending;
> > > > > > > +#endif /* #ifdef CONFIG_ACPI_SLEEP */
> > > > > >
> > > > > > __maybe_unused ?
> > > > >
> > > > > Are the compiler and linker smart enough to get rid of the storage in
> > > > > case it really isn't used? (Not that the storage for a bool is worth
> > > > > worrying about, but...)
> > > >
> > > > GCC with optimization enabled will get rid of the storage even without
> > > > __maybe_unused.
> > >
> > > OK, that should allow me to get rid of a few ifdefs, then! For this one,
> > > please see below.
> > >
> > > Thanx, Paul
> > >
> > > ------------------------------------------------------------------------
> > >
> > > acpi: fix pwr_btn_event_pending build error
> > >
> > > A recent build for KVM on x86 resulted in the following build error:
> > >
> > > drivers/acpi/sleep.c:60:13: warning: ‘pwr_btn_event_pending’ defined but not
> > > +used [-Wunused-variable]
> > >
> > > This patch silences this error.
> > >
> > > Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
> >
> > Well, I prefer the one below.
>
> Works for me!

Cool. :-)

I'll resend it just in case there was some confusion somewhere.

Thanks,
Rafael

> > ---
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > Subject: ACPI / PM: Fix build warning in sleep.c for CONFIG_ACPI_SLEEP unset
> >
> > If CONFIG_ACPI_SLEEP is unset, the compiler complains that
> > pwr_btn_event_pending is defined but not used. To silence the
> > warning, move the definition of pwr_btn_event_pending under an
> > apprporiate #ifdef.
> >
> > Reported-by: Paul E. McKenney <paul.mckenney@linaro.org>
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > ---
> > drivers/acpi/sleep.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: linux/drivers/acpi/sleep.c
> > ===================================================================
> > --- linux.orig/drivers/acpi/sleep.c
> > +++ linux/drivers/acpi/sleep.c
> > @@ -57,7 +57,6 @@ MODULE_PARM_DESC(gts, "Enable evaluation
> > MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
> >
> > static u8 sleep_states[ACPI_S_STATE_COUNT];
> > -static bool pwr_btn_event_pending;
> >
> > static void acpi_sleep_tts_switch(u32 acpi_state)
> > {
> > @@ -110,6 +109,7 @@ static int acpi_sleep_prepare(u32 acpi_s
> >
> > #ifdef CONFIG_ACPI_SLEEP
> > static u32 acpi_target_sleep_state = ACPI_STATE_S0;
> > +static bool pwr_btn_event_pending;
> >
> > /*
> > * The ACPI specification wants us to save NVS memory regions during hibernation
> >
>
>
>