1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 6bb2dd3c3a71..7628cd1bc36a 100644
--- a/Documentation/ABI/testing/sysfs-devices-power
+++ b/Documentation/ABI/testing/sysfs-devices-power
@@ -147,3 +147,21 @@ Description:
                 milliseconds.  This attribute is read-only.  If the device is
                 not enabled to wake up the system from sleep states, this
                 attribute is empty.
+
+What:           /sys/devices/.../power/autosuspend_delay_ms
+Date:           September 2010
+Contact:        Alan Stern <stern@rowland.harvard.edu>
+Description:
+                The /sys/devices/.../power/autosuspend_delay_ms attribute
+                contains the autosuspend delay value (in milliseconds).  Some
+                drivers do not want their device to suspend as soon as it
+                becomes idle at run time; they want the device to remain
+                inactive for a certain minimum period of time first.  That
+                period is called the autosuspend delay.  Negative values will
+                prevent the device from being suspended at run time (similar
+                to writing "on" to the power/control attribute).  Values >=
+                1000 will cause the autosuspend timer expiration to be rounded
+                up to the nearest second.
+
+                Not all drivers support this attribute.  If it isn't supported,
+                attempts to read or write it will yield I/O errors.