USB: Export if an interface driver supports autosuspend.
Create a new sysfs file per interface named supports_autosuspend. This
file returns true if an interface driver's .supports_autosuspend flag is
set. It also returns true if the interface is unclaimed (since the USB
core will autosuspend a device if an interface is not claimed).
This new sysfs file will be useful for user space scripts to test whether
a USB device correctly auto-suspends.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 11a3c16..df6c8a0 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -85,3 +85,19 @@
Users:
PowerTOP <power@bughost.org>
http://www.lesswatts.org/projects/powertop/
+
+What: /sys/bus/usb/device/<busnum>-<devnum>...:<config num>-<interface num>/supports_autosuspend
+Date: January 2008
+KernelVersion: 2.6.27
+Contact: Sarah Sharp <sarah.a.sharp@intel.com>
+Description:
+ When read, this file returns 1 if the interface driver
+ for this interface supports autosuspend. It also
+ returns 1 if no driver has claimed this interface, as an
+ unclaimed interface will not stop the device from being
+ autosuspended if all other interface drivers are idle.
+ The file returns 0 if autosuspend support has not been
+ added to the driver.
+Users:
+ USB PM tool
+ git://git.moblin.org/users/sarah/usb-pm-tool/