linux-kernel - [PATCH 4/4] ACPI: PM: Avoid cache flush on entering S4

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Date:   Mon,  6 Dec 2021 15:29:52 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:     rafael@...nel.org
Cc:     ak@...ux.intel.com, bp@...en8.de, dan.j.williams@...el.com,
        dave.hansen@...ux.intel.com, hpa@...or.com,
        kirill.shutemov@...ux.intel.com, knsathya@...nel.org,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
        mingo@...hat.com, rjw@...ysocki.net,
        sathyanarayanan.kuppuswamy@...ux.intel.com, tglx@...utronix.de,
        tony.luck@...el.com, x86@...nel.org
Subject: [PATCH 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@...ux.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 */
-- 
2.32.0