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

[Lan Tianyu]

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@xxxxxxxxx>
---
 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@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/