X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2FABI%2Ftesting%2Fsysfs-bus-usb;h=11a3c1682cecb87e16514249d6877a18608ccf01;hb=a42dde04152750426cc620fd277e80fffae2f65a;hp=f9937add033d833e869fb996565bb74ff2f5233d;hpb=49e1900d4cc2e7bcecb681fe60f0990bec2dcce8;p=linux-2.6

diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index f9937add03..11a3c1682c 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -39,3 +39,49 @@ Description:
 		If you want to suspend a device immediately but leave it
 		free to wake up in response to I/O requests, you should
 		write "0" to power/autosuspend.
+
+What:		/sys/bus/usb/devices/.../power/persist
+Date:		May 2007
+KernelVersion:	2.6.23
+Contact:	Alan Stern <stern@rowland.harvard.edu>
+Description:
+		If CONFIG_USB_PERSIST is set, then each USB device directory
+		will contain a file named power/persist.  The file holds a
+		boolean value (0 or 1) indicating whether or not the
+		"USB-Persist" facility is enabled for the device.  Since the
+		facility is inherently dangerous, it is disabled by default
+		for all devices except hubs.  For more information, see
+		Documentation/usb/persist.txt.
+
+What:		/sys/bus/usb/device/.../power/connected_duration
+Date:		January 2008
+KernelVersion:	2.6.25
+Contact:	Sarah Sharp <sarah.a.sharp@intel.com>
+Description:
+		If CONFIG_PM and CONFIG_USB_SUSPEND are enabled, then this file
+		is present.  When read, it returns the total time (in msec)
+		that the USB device has been connected to the machine.  This
+		file is read-only.
+Users:
+		PowerTOP <power@bughost.org>
+		http://www.lesswatts.org/projects/powertop/
+
+What:		/sys/bus/usb/device/.../power/active_duration
+Date:		January 2008
+KernelVersion:	2.6.25
+Contact:	Sarah Sharp <sarah.a.sharp@intel.com>
+Description:
+		If CONFIG_PM and CONFIG_USB_SUSPEND are enabled, then this file
+		is present.  When read, it returns the total time (in msec)
+		that the USB device has been active, i.e. not in a suspended
+		state.  This file is read-only.
+
+		Tools can use this file and the connected_duration file to
+		compute the percentage of time that a device has been active.
+		For example,
+		echo $((100 * `cat active_duration` / `cat connected_duration`))
+		will give an integer percentage.  Note that this does not
+		account for counter wrap.
+Users:
+		PowerTOP <power@bughost.org>
+		http://www.lesswatts.org/projects/powertop/