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

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(-)

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!

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?

On Wed, Dec 8, 2021 at 5:04 PM Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
>
> 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?

Just for the [4/4].

> Do I need to do something for 2/4 and 3/4?

For [2/4] you do as per the comment and let me reply to the [3/4].