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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-01-24 12:50:09 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-01-24 12:50:09 +0100
commitb1c0f99bfb89cd9b42e3119ab822a8102fa87909 (patch)
tree4a6f07a25ca239bb579cc583c67b92ab451d40b7 /Documentation/ABI
parentACPI / PM: Expose power states of ACPI devices to user space (diff)
downloadlinux-b1c0f99bfb89cd9b42e3119ab822a8102fa87909.tar.xz
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ACPI / PM: Expose current status of ACPI power resources
Since ACPI power resources are going to be used more extensively on new hardware platforms, it becomes necessary for user space (powertop in particular) to observe some properties of those resources for diagnostics purposes. For this reason, expose the current status of each ACPI power resource to user space via sysfs by adding a new resource_in_use attribute to the sysfs directory representing the given power resource. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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+What: /sys/devices/.../resource_in_use
+Date: January 2013
+Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+ The /sys/devices/.../resource_in_use attribute is only present
+ for device objects representing ACPI power resources.
+
+ If present, it contains a number (0 or 1) representing the
+ current status of the given power resource (0 means that the
+ resource is not in use and therefore it has been turned off).
+
+ This attribute is read-only.