Documentation/ABI/testing/sysfs-devices-real_power_state

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-devices-real_power_state

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-devices-real_power_state
Extension
[no extension]
Size
1026 bytes
Lines
24
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

What:		/sys/devices/.../real_power_state
Date:		January 2013
Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Description:
		The /sys/devices/.../real_power_state attribute is only present
		for device objects representing ACPI device nodes that provide
		power management methods and use ACPI power resources for power
		management.

		If present, it contains a string representing the real ACPI
		power state of the given device node as returned by the _PSC
		control method or inferred from the configuration of power
		resources.  Its possible values, "D0", "D1", "D2", "D3hot", and
		"D3cold", reflect the power state names defined by the ACPI
		specification (ACPI 4 and above).

		In some situations the value of this attribute may be different
		from the value of the /sys/devices/.../power_state attribute for
		the same device object.  If that happens, some shared power
		resources used by the device node are only ON because of some
		other devices using them at the moment.

		This attribute is read-only.

Annotation

Implementation Notes