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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/ABI/stable
parentc3b92c8787367a8bb53d57d9789b558f1295cc96 (diff)
downloadlinux-bcache-362b646062b2073bd5c38efb42171d86e4f717e6.tar.zst
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/ABI/stable')
-rw-r--r--Documentation/ABI/stable/sysfs-acpi-pmprofile22
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diff --git a/Documentation/ABI/stable/sysfs-acpi-pmprofile b/Documentation/ABI/stable/sysfs-acpi-pmprofile
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+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