diff options
| author | Rafael J. Wysocki | 2017-07-31 23:43:18 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki | 2017-08-05 01:51:26 +0200 |
| commit | e870c6c87cf9484090d28f2a68aa29e008960c93 (patch) | |
| tree | 9d19e498e1ed8bcc864b66d5817f03d09cc6ddcd /Documentation/power | |
| parent | 635173a17b0323c28a39fb06fa36d876035cd2b9 (diff) | |
ACPI / PM: Prefer suspend-to-idle over S3 on some systems
Modify the ACPI system sleep support setup code to select
suspend-to-idle as the default system sleep state if
(1) the ACPI_FADT_LOW_POWER_S0 flag is set in the FADT and
(2) the Low Power Idle S0 _DSM interface has been discovered and
(3) the default sleep state was not selected from the kernel command
line.
The main motivation for this change is that systems where the (1) and
(2) conditions are met typically ship with OSes that don't exercise
the S3 path in the platform firmware which remains untested and turns
out to be non-functional at least in some cases.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@dell.com>
Diffstat (limited to 'Documentation/power')
| -rw-r--r-- | Documentation/power/states.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/power/states.txt b/Documentation/power/states.txt index bc4548245a24..205e45ad7c65 100644 --- a/Documentation/power/states.txt +++ b/Documentation/power/states.txt @@ -35,7 +35,9 @@ only one way to cause the system to go into the Suspend-To-RAM state (write The default suspend mode (ie. the one to be used without writing anything into /sys/power/mem_sleep) is either "deep" (if Suspend-To-RAM is supported) or "s2idle", but it can be overridden by the value of the "mem_sleep_default" -parameter in the kernel command line. +parameter in the kernel command line. On some ACPI-based systems, depending on +the information in the FADT, the default may be "s2idle" even if Suspend-To-RAM +is supported. The properties of all of the sleep states are described below. |