admin-guide/pm/sleep-states.rst

23 hibernation and up to three variants of system suspend.  The sleep states that
28 Suspend-to-Idle
31 This is a generic, pure software, light-weight variant of system suspend (also
43 or :ref:`suspend-to-RAM <s2ram>`, or it can be used in addition to any of the
44 deeper system suspend variants to provide reduced resume latency.  It is always
58 I/O devices into low-power states, which is done for :ref:`suspend-to-idle
61 allow more energy to be saved relative to :ref:`suspend-to-idle <s2idle>`, but
65 reduced relative to :ref:`suspend-to-idle <s2idle>` and it may be necessary to
70 core system suspend subsystem.  On ACPI-based systems this state is mapped to
75 Suspend-to-RAM
98 relative to :ref:`suspend-to-idle <s2idle>` and :ref:`standby <standby>` and it
104 suspend subsystem.  On ACPI-based systems it is mapped to the S3 system state
112 This state (also referred to as Suspend-to-Disk or STD) offers the greatest
114 for system suspend.  However, it requires some low-level code for resuming the
117 Hibernation is significantly different from any of the system suspend variants.
153 Basic ``sysfs`` Interfaces for System Suspend and Hibernation
169 	:ref:`hibernation <hibernation>`, :ref:`suspend-to-idle <s2idle>` and
179 	suspend	variants and allows user space to select the variant to be
183 	and "deep".  The "s2idle" string always represents :ref:`suspend-to-idle
185 	:ref:`standby <standby>` and :ref:`suspend-to-RAM <s2ram>`,
189 	suspend variant represented by it to be associated with the "mem" string
190 	in the ``state`` file.  The string representing the suspend variant
194 	If the kernel does not support system suspend, this file is not present.
197 	This file controls the operating mode of hibernation (Suspend-to-Disk).
220 	``suspend``
221 		Hybrid system suspend.  Put the system into the suspend sleep
227 		It is available if system suspend is supported.
260 	This file controls the "PM trace" mechanism saving the last suspend
263 	during system suspend or resume (which is more common) more effectively.
265 	If it contains "1", the fingerprint of each suspend/resume event point
275 :ref:`suspend-to-idle <s2idle>` state.  The first one is to write "freeze"
282 system go into the :ref:`suspend-to-RAM <s2ram>` state (write "deep" into
285 The default suspend variant (ie. the one to be used without writing anything
287 supporting :ref:`suspend-to-RAM <s2ram>`) or "s2idle", but it can be overridden
290 default may be "s2idle" even if :ref:`suspend-to-RAM <s2ram>` is supported in