linux-kernel - [PATCH] ACPI/NVS: Not save NVS region for new machines to accelerate S3

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1405662922-23606-1-git-send-email-tianyu.lan@intel.com>
Date:	Fri, 18 Jul 2014 13:55:22 +0800
From:	Lan Tianyu <tianyu.lan@...el.com>
To:	rjw@...ysocki.net, lenb@...nel.org
Cc:	Lan Tianyu <tianyu.lan@...el.com>, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] ACPI/NVS: Not save NVS region for new machines to accelerate S3

NVS region is saved and restored unconditionally for machines without
nvs_nosave quirk during S3. Tested some new machines and the operation
is not necessary. Saving NVS region also affects S2RAM speed. The time of
NVS saving and restoring depends on the size of NVS region and it consumes
7~10ms normally.

This patch is to make machines produced from 2012 to now not saving NVS region
to accelerate S3.

Signed-off-by: Lan Tianyu <tianyu.lan@...el.com>
---
 drivers/acpi/sleep.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index b3e3cc7..896d8be 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -322,7 +322,12 @@ static struct dmi_system_id acpisleep_dmi_table[] __initdata = {
 
 static void acpi_sleep_dmi_check(void)
 {
+	int year;
+
 	dmi_check_system(acpisleep_dmi_table);
+
+	if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year >= 2012)
+		acpi_nvs_nosave_s3();
 }
 
 /**
-- 
1.8.4.rc0.1.g8f6a3e5.dirty

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/