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1 | What: /sys/devices/.../power_state | ||
2 | Date: January 2013 | ||
3 | Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | ||
4 | Description: | ||
5 | The /sys/devices/.../power_state attribute is only present for | ||
6 | device objects representing ACPI device nodes that provide power | ||
7 | management methods. | ||
8 | |||
9 | If present, it contains a string representing the current ACPI | ||
10 | power state of the given device node. Its possible values, | ||
11 | "D0", "D1", "D2", "D3hot", and "D3cold", reflect the power state | ||
12 | names defined by the ACPI specification (ACPI 4 and above). | ||
13 | |||
14 | If the device node uses shared ACPI power resources, this state | ||
15 | determines a list of power resources required not to be turned | ||
16 | off. However, some power resources needed by the device node in | ||
17 | higher-power (lower-number) states may also be ON because of | ||
18 | some other devices using them at the moment. | ||
19 | |||
20 | This attribute is read-only. | ||