Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-power')
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 6bb2dd3c3a7..7628cd1bc36 100644
@@ -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.
+Date: September 2010
+Contact: Alan Stern <email@example.com>
+ 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.