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

From: Rafael J. Wysocki
Date: Tue Jul 22 2014 - 19:22:16 EST


On Friday, July 18, 2014 01:55:22 PM Lan Tianyu wrote:
> 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();

I'd prefer the ordering here to be different so that individual quirks
could be used to change the date-based wholesale behavior.

> }
>
> /**
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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