What: /sys/devices/.../power_state Date: January 2013 Contact: Rafael J. Wysocki 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.