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ACPI: PM: Remove redundant cache flushing 

ACPICA code takes care about cache flushing on S1/S2/S3 in
acpi_hw_extended_sleep() and acpi_hw_legacy_sleep().

acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state()
for S1 or x86_acpi_suspend_lowlevel() for S3.

acpi_sleep_prepare() call tree:
  __acpi_pm_prepare()
    acpi_pm_prepare()
      acpi_suspend_ops::prepare_late()
      acpi_hibernation_ops::pre_snapshot()
      acpi_hibernation_ops::prepare()
    acpi_suspend_begin_old()
      acpi_suspend_begin_old::begin()
  acpi_hibernation_begin_old()
    acpi_hibernation_ops_old::acpi_hibernation_begin_old()
  acpi_power_off_prepare()
    pm_power_off_prepare()

Hibernation (S4) and Power Off (S5) don't require cache flushing, so
the only interesting callsites are acpi_suspend_ops::prepare_late()
and acpi_suspend_begin_old::begin(). Both of them have cache flush
on ->enter() operation in acpi_suspend_enter().

Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and
acpi_suspend_enter().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Kirill A. Shutemov 2021-12-09 16:08:02 +03:00 committed by Rafael J. Wysocki
parent 53d01e2016
commit 3c89857a66
1 changed files with 0 additions and 3 deletions
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3
drivers/acpi/sleep.c
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@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state)
acpi_set_waking_vector(acpi_wakeup_address);
}
ACPI_FLUSH_CPU_CACHE();
#endif
pr_info("Preparing to enter system sleep state S%d\n", acpi_state);
acpi_enable_wakeup_devices(acpi_state);
@ -566,8 +565,6 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
u32 acpi_state = acpi_target_sleep_state;
int error;
ACPI_FLUSH_CPU_CACHE();
trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true);
switch (acpi_state) {
case ACPI_STATE_S1: