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Subject[PATCH] Revert "ACPI: processor: idle: Only flush cache on entering C3"
This reverts commit 87ebbb8c612b1214f227ebb8f25442c6d163e802.

ACPI processor power states can be transitioned in two distinct
situations: 1. when CPU goes idle and 2. before CPU goes offline
("playing dead") to suspend or hibernate. Case 1 is handled by
acpi_idle_enter or acpi_idle_enter_s2idle. Case 2 is handled by

It is necessary to flush CPU caches in case 2 even if it is not
required to transit ACPI processor power states as CPU will go
offline soon. However, the reverted commit incorrectly removed CPU
cache flushing in such a condition. In fact, it made resuming from
suspend-to-RAM occasionally fail on Lenovo ThinkPad C13 Yoga.

Signed-off-by: Akihiko Odaki <>
drivers/acpi/processor_idle.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f8e9fa82cb9b..05b3985a1984 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -570,8 +570,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);

- if (cx->type == ACPI_STATE_C3)

while (1) {

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