Re: [PATCH v2 2/6] Drivers: hv: allow non ACPI compilation for hv_is_hibernation_supported

From: Saurabh Singh Sengar
Date: Thu Feb 02 2023 - 09:50:12 EST


On Wed, Feb 01, 2023 at 05:47:44PM +0000, Michael Kelley (LINUX) wrote:
> From: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> Sent: Tuesday, January 31, 2023 10:10 AM
> >
> > acpi_sleep_state_supported API is only define for CONFIG_ACPI flag and
> > thus it can't be used for non-ACPI builds. Initaly there won't be
>
> s/Initaly/Initially/

OK

>
> > hibernate support for non ACPI builds.
>
> s/hibernate/hibernation/

OK

>
> >
> > This change will help adding device tree support in subsequent commits.
> >
> > Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/hv/hv_common.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> > index 52a6f89ccdbd..370ec20d1993 100644
> > --- a/drivers/hv/hv_common.c
> > +++ b/drivers/hv/hv_common.c
> > @@ -234,7 +234,11 @@ EXPORT_SYMBOL_GPL(hv_setup_dma_ops);
> >
> > bool hv_is_hibernation_supported(void)
> > {
> > +#ifdef CONFIG_ACPI
> > return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
> > +#else
> > + return false;
> > +#endif
>
> Is this patch needed? If CONFIG_ACPI is not set, then per
> arch/x86/Kconfig, CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT
> is not selected. In that case, the #ifdef in include/acpi/acpi_bus.h
> provides a stub for acpi_sleep_state_supported() that returns "false".
> So it seems like the existing code should compile and correctly return
> "false" when CONFIG_ACPI is not set.

You are right, if CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT is not set
acpi_sleep_state_supported will return false, but this is applicable only
when CONFIG_ACPI is enable. If CONFIG_ACPI is not enable both these
functions are not defined.

Regards,
Saurabh


>
> Michael
>
> > }
> > EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
> >
> > --
> > 2.25.1