diff mbox series

[3/4] ACPI: processor idle: Only flush cache on entering C3

Message ID 20211206122952.74139-4-kirill.shutemov@linux.intel.com
State Accepted
Commit 87ebbb8c612b1214f227ebb8f25442c6d163e802
Headers show
Series ACPI/ACPICA: Only flush caches on S1/S2/S3 and C3 | expand

Commit Message

Kirill A. Shutemov Dec. 6, 2021, 12:29 p.m. UTC 
According to the ACPI spec v6.4, section 8.2, cache flushing required
on entering C3 power state.

Avoid flushing cache on entering other power states.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 drivers/acpi/processor_idle.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 76ef1bcc8848..01495aca850e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -567,7 +567,8 @@  static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 {
 	struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 
-	ACPI_FLUSH_CPU_CACHE();
+	if (cx->type == ACPI_STATE_C3)
+		ACPI_FLUSH_CPU_CACHE();
 
 	while (1) {