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authorThomas Renninger <trenn@suse.de>2011-11-04 03:33:46 +0100
committerLen Brown <len.brown@intel.com>2011-11-06 20:48:42 -0500
commit362b646062b2073bd5c38efb42171d86e4f717e6 (patch)
tree6c98cdb7aa5d9be22e2b24ca06b822455ef4b9f5 /Documentation
parentc3b92c8787367a8bb53d57d9789b558f1295cc96 (diff)
downloadlinux-362b646062b2073bd5c38efb42171d86e4f717e6.tar.gz
ACPI: Export FADT pm_profile integer value to userspace
There are a lot userspace approaches to detect the usage of the
platform (laptop, workstation, server, ...) and adjust kernel tunables
accordingly (io/process scheduler, power management, ...).

These approaches need constant maintaining and are ugly to implement
(detect PCMCIA controller -> laptop,
does not work on recent systems anymore, ...)
On ACPI systems there is an easy and reliable way (if implemented
in BIOS and most recent platforms have this value set).
-> export it to userspace.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-acpi-pmprofile22
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-acpi-pmprofile b/Documentation/ABI/stable/sysfs-acpi-pmprofile
new file mode 100644
index 000000000000..964c7a8afb26
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-acpi-pmprofile
@@ -0,0 +1,22 @@
+What: 		/sys/firmware/acpi/pm_profile
+Date:		03-Nov-2011
+KernelVersion:	v3.2
+Contact:	linux-acpi@vger.kernel.org
+Description: 	The ACPI pm_profile sysfs interface exports the platform
+		power management (and performance) requirement expectations
+		as provided by BIOS. The integer value is directly passed as
+		retrieved from the FADT ACPI table.
+Values:         For possible values see ACPI specification:
+		5.2.9 Fixed ACPI Description Table (FADT)
+		Field: Preferred_PM_Profile
+
+		Currently these values are defined by spec:
+		0 Unspecified
+		1 Desktop
+		2 Mobile
+		3 Workstation
+		4 Enterprise Server
+		5 SOHO Server
+		6 Appliance PC
+		7 Performance Server
+		>7 Reserved