| What: /sys/devices/.../power_state |
| Date: January 2013 |
| Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| Description: |
| The /sys/devices/.../power_state attribute is only present for |
| device objects representing ACPI device nodes that provide power |
| management methods. |
| |
| If present, it contains a string representing the current ACPI |
| power state of the given device node. Its possible values, |
| "D0", "D1", "D2", "D3hot", and "D3cold", reflect the power state |
| names defined by the ACPI specification (ACPI 4 and above). |
| |
| If the device node uses shared ACPI power resources, this state |
| determines a list of power resources required not to be turned |
| off. However, some power resources needed by the device node in |
| higher-power (lower-number) states may also be ON because of |
| some other devices using them at the moment. |
| |
| This attribute is read-only. |
