From: Damien Le Moal dlemoal@kernel.org
[ Upstream commit ed62a62a18bc144f73eadf866ae46842e8f6606e ]
Improve the description of the possible default SATA link power management policies and add the missing description for policy 5. No functional changes.
Fixes: a5ec5a7bfd1f ("ata: ahci: Support state with min power but Partial low power state") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal dlemoal@kernel.org Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Niklas Cassel cassel@kernel.org [ Adjust context ] Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ata/Kconfig | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig index 42b51c9812a0..188707d2970e 100644 --- a/drivers/ata/Kconfig +++ b/drivers/ata/Kconfig @@ -117,7 +117,7 @@ config SATA_AHCI
config SATA_MOBILE_LPM_POLICY int "Default SATA Link Power Management policy for low power chipsets" - range 0 4 + range 0 5 default 0 depends on SATA_AHCI help @@ -126,15 +126,32 @@ config SATA_MOBILE_LPM_POLICY chipsets are typically found on most laptops but desktops and servers now also widely use chipsets supporting low power modes.
- The value set has the following meanings: + Each policy combines power saving states and features: + - Partial: The Phy logic is powered but is in a reduced power + state. The exit latency from this state is no longer than + 10us). + - Slumber: The Phy logic is powered but is in an even lower power + state. The exit latency from this state is potentially + longer, but no longer than 10ms. + - DevSleep: The Phy logic may be powered down. The exit latency from + this state is no longer than 20 ms, unless otherwise + specified by DETO in the device Identify Device Data log. + - HIPM: Host Initiated Power Management (host automatically + transitions to partial and slumber). + - DIPM: Device Initiated Power Management (device automatically + transitions to partial and slumber). + + The possible values for the default SATA link power management + policies are: 0 => Keep firmware settings - 1 => Maximum performance - 2 => Medium power - 3 => Medium power with Device Initiated PM enabled - 4 => Minimum power - - Note "Minimum power" is known to cause issues, including disk - corruption, with some disks and should not be used. + 1 => No power savings (maximum performance) + 2 => HIPM (Partial) + 3 => HIPM (Partial) and DIPM (Partial and Slumber) + 4 => HIPM (Partial and DevSleep) and DIPM (Partial and Slumber) + 5 => HIPM (Slumber and DevSleep) and DIPM (Partial and Slumber) + + Excluding the value 0, higher values represent policies with higher + power savings.
config SATA_AHCI_PLATFORM tristate "Platform AHCI SATA support"