Re: [PATCH 4/4] ACPI: PM: Avoid cache flush on entering S4

Kirill A. Shutemov
2021-12-08T16:04:58Z

On Wed, Dec 08, 2021 at 04:10:52PM +0100, Rafael J. Wysocki wrote:
> On Mon, Dec 6, 2021 at 1:30 PM Kirill A. Shutemov
> <kirill.shutemov@linux.intel.com> wrote:
> >
> > According to the ACPI spec v6.4, section 16.2 the cache flushing
> > required on entering to S1, S2, and S3.
> >
> > No need to flush caches on hibernation (S4).
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > ---
> > drivers/acpi/sleep.c | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> > index 14e8df0ac762..8166d863ed6b 100644
> > --- a/drivers/acpi/sleep.c
> > +++ b/drivers/acpi/sleep.c
> > @@ -902,8 +902,6 @@ static int acpi_hibernation_enter(void)
> > {
> > acpi_status status = AE_OK;
> >
> > - ACPI_FLUSH_CPU_CACHE();
> > -
> > /* This shouldn't return. If it returns, we have a problem */
> > status = acpi_enter_sleep_state(ACPI_STATE_S4);
> > /* Reprogram control registers */
> > --
>
> Applied (with some edits in the subject and changelog) as 5.17 material, thanks!

Is it for the series or only 4/4? Do I need to do something for 2/4 and
3/4?

--
Kirill A. Shutemov