Re: [PATCH 2/2] ACPI: let BIOS fall back to legacy handling if PRM disabled

From: Rafael J. Wysocki
Date: Fri Jul 02 2021 - 10:02:36 EST


On Fri, Jul 2, 2021 at 1:37 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Fri, Jul 2, 2021 at 9:03 AM Aubrey Li <aubrey.li@xxxxxxxxx> wrote:
> >
> > Based on _OSC PRM bit, BIOS can choose switch from legacy handling
> > to using PRM. So if CONFIG_ACPI_PRMT is disabled, this bit should
> > not be set to let BIOS fall back to the legacy handling (such as SMI).
> >
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
> > ---
> > drivers/acpi/bus.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > index 60fb6a84..30a3d4a 100644
> > --- a/drivers/acpi/bus.c
> > +++ b/drivers/acpi/bus.c
> > @@ -303,7 +303,9 @@ static void acpi_bus_osc_negotiate_platform_control(void)
> >
> > capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
> > capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
> > +#ifdef CONFIG_ACPI_PRMT
> > capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PRM_SUPPORT;
> > +#endif
>
> What about using if (IS_ENABLED()) instead of #ifdef?

I've made this change myself and applied the patch with a rewritten
changelog and under a different subject ("ACPI: Do not singal PRM
support if not enabled").

Thanks!