diff options
Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-power | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 431bfd7e65c..6123c523bfd 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -51,3 +51,29 @@ Description: drivers. Changing this attribute to "on" prevents the driver from power managing the device at run time. Doing that while the device is suspended causes it to be woken up. + +What: /sys/devices/.../power/async +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../async attribute allows the user space to + enable or diasble the device's suspend and resume callbacks to + be executed asynchronously (ie. in separate threads, in parallel + with the main suspend/resume thread) during system-wide power + transitions (eg. suspend to RAM, hibernation). + + All devices have one of the following two values for the + power/async file: + + + "enabled\n" to permit the asynchronous suspend/resume; + + "disabled\n" to forbid it; + + The value of this attribute may be changed by writing either + "enabled", or "disabled" to it. + + It generally is unsafe to permit the asynchronous suspend/resume + of a device unless it is certain that all of the PM dependencies + of the device are known to the PM core. However, for some + devices this attribute is set to "enabled" by bus type code or + device drivers and in that cases it should be safe to leave the + default value. |