Commit ed62a62a authored by Damien Le Moal's avatar Damien Le Moal
Browse files

ata: Fix SATA_MOBILE_LPM_POLICY description in Kconfig 



Improve the description of the possible default SATA link power
management policies and add the missing description for policy 5.
No functional changes.

Fixes: a5ec5a7b ("ata: ahci: Support state with min power but Partial low power state")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarNiklas Cassel <cassel@kernel.org>
parent cb45e3ff

drivers/ata/Kconfig

+26 −10
Original line number Diff line number Diff line
@@ -117,23 +117,39 @@ config SATA_AHCI 


config SATA_MOBILE_LPM_POLICY

	int "Default SATA Link Power Management policy"

	range 0 4

	range 0 5

	default 3

	depends on SATA_AHCI

	help

	  Select the Default SATA Link Power Management (LPM) policy to use

	  for chipsets / "South Bridges" supporting low-power modes. Such

	  chipsets are ubiquitous across laptops, desktops and servers.



	  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"