Documentation/ABI/testing/sysfs-power

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

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-power
Extension
[no extension]
Size
18554 bytes
Lines
473
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/power/
Date:		August 2006
Contact:	Rafael J. Wysocki <rafael@kernel.org>
Description:
		The /sys/power directory will contain files that will
		provide a unified interface to the power management
		subsystem.

What:		/sys/power/state
Date:		November 2016
Contact:	Rafael J. Wysocki <rafael@kernel.org>
Description:
		The /sys/power/state file controls system sleep states.
		Reading from this file returns the available sleep state
		labels, which may be "mem" (suspend), "standby" (power-on
		suspend), "freeze" (suspend-to-idle) and "disk" (hibernation).

		Writing one of the above strings to this file causes the system
		to transition into the corresponding state, if available.

		See Documentation/admin-guide/pm/sleep-states.rst for more
		information.

What:		/sys/power/mem_sleep
Date:		November 2016
Contact:	Rafael J. Wysocki <rafael@kernel.org>
Description:
		The /sys/power/mem_sleep file controls the operating mode of
		system suspend.  Reading from it returns the available modes
		as "s2idle" (always present), "shallow" and "deep" (present if
		supported).  The mode that will be used on subsequent attempts
		to suspend the system (by writing "mem" to the /sys/power/state
		file described above) is enclosed in square brackets.

		Writing one of the above strings to this file causes the mode
		represented by it to be used on subsequent attempts to suspend
		the system.

		See Documentation/admin-guide/pm/sleep-states.rst for more
		information.

What:		/sys/power/disk
Date:		September 2006
Contact:	Rafael J. Wysocki <rafael@kernel.org>
Description:
		The /sys/power/disk file controls the operating mode of the
		suspend-to-disk mechanism.  Reading from this file returns
		the name of the method by which the system will be put to
		sleep on the next suspend.  There are four methods supported:

		'firmware' - means that the memory image will be saved to disk
		by some firmware, in which case we also assume that the
		firmware will handle the system suspend.

		'platform' - the memory image will be saved by the kernel and
		the system will be put to sleep by the platform driver (e.g.
		ACPI or other PM registers).

		'shutdown' - the memory image will be saved by the kernel and
		the system will be powered off.

		'reboot' - the memory image will be saved by the kernel and
		the system will be rebooted.

		Additionally, /sys/power/disk can be used to turn on one of the
		two testing modes of the suspend-to-disk mechanism: 'testproc'
		or 'test'.  If the suspend-to-disk mechanism is in the
		'testproc' mode, writing 'disk' to /sys/power/state will cause
		the kernel to disable nonboot CPUs and freeze tasks, wait for 5
		seconds, unfreeze tasks and enable nonboot CPUs.  If it is in

Annotation

Implementation Notes