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-rw-r--r--Documentation/power/devices.txt15
-rw-r--r--Documentation/power/interface.txt4
-rw-r--r--Documentation/power/states.txt20
3 files changed, 27 insertions, 12 deletions
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 504dfe4d52eb..a66c9821b5ce 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt
@@ -268,7 +268,7 @@ situations.
268System Power Management Phases 268System Power Management Phases
269------------------------------ 269------------------------------
270Suspending or resuming the system is done in several phases. Different phases 270Suspending or resuming the system is done in several phases. Different phases
271are used for standby or memory sleep states ("suspend-to-RAM") and the 271are used for freeze, standby, and memory sleep states ("suspend-to-RAM") and the
272hibernation state ("suspend-to-disk"). Each phase involves executing callbacks 272hibernation state ("suspend-to-disk"). Each phase involves executing callbacks
273for every device before the next phase begins. Not all busses or classes 273for every device before the next phase begins. Not all busses or classes
274support all these callbacks and not all drivers use all the callbacks. The 274support all these callbacks and not all drivers use all the callbacks. The
@@ -309,7 +309,8 @@ execute the corresponding method from dev->driver->pm instead if there is one.
309 309
310Entering System Suspend 310Entering System Suspend
311----------------------- 311-----------------------
312When the system goes into the standby or memory sleep state, the phases are: 312When the system goes into the freeze, standby or memory sleep state,
313the phases are:
313 314
314 prepare, suspend, suspend_late, suspend_noirq. 315 prepare, suspend, suspend_late, suspend_noirq.
315 316
@@ -368,7 +369,7 @@ the devices that were suspended.
368 369
369Leaving System Suspend 370Leaving System Suspend
370---------------------- 371----------------------
371When resuming from standby or memory sleep, the phases are: 372When resuming from freeze, standby or memory sleep, the phases are:
372 373
373 resume_noirq, resume_early, resume, complete. 374 resume_noirq, resume_early, resume, complete.
374 375
@@ -433,8 +434,8 @@ the system log.
433 434
434Entering Hibernation 435Entering Hibernation
435-------------------- 436--------------------
436Hibernating the system is more complicated than putting it into the standby or 437Hibernating the system is more complicated than putting it into the other
437memory sleep state, because it involves creating and saving a system image. 438sleep states, because it involves creating and saving a system image.
438Therefore there are more phases for hibernation, with a different set of 439Therefore there are more phases for hibernation, with a different set of
439callbacks. These phases always run after tasks have been frozen and memory has 440callbacks. These phases always run after tasks have been frozen and memory has
440been freed. 441been freed.
@@ -485,8 +486,8 @@ image forms an atomic snapshot of the system state.
485 486
486At this point the system image is saved, and the devices then need to be 487At this point the system image is saved, and the devices then need to be
487prepared for the upcoming system shutdown. This is much like suspending them 488prepared for the upcoming system shutdown. This is much like suspending them
488before putting the system into the standby or memory sleep state, and the phases 489before putting the system into the freeze, standby or memory sleep state,
489are similar. 490and the phases are similar.
490 491
491 9. The prepare phase is discussed above. 492 9. The prepare phase is discussed above.
492 493
diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index c537834af005..f1f0f59a7c47 100644
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -7,8 +7,8 @@ running. The interface exists in /sys/power/ directory (assuming sysfs
7is mounted at /sys). 7is mounted at /sys).
8 8
9/sys/power/state controls system power state. Reading from this file 9/sys/power/state controls system power state. Reading from this file
10returns what states are supported, which is hard-coded to 'standby' 10returns what states are supported, which is hard-coded to 'freeze',
11(Power-On Suspend), 'mem' (Suspend-to-RAM), and 'disk' 11'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and 'disk'
12(Suspend-to-Disk). 12(Suspend-to-Disk).
13 13
14Writing to this file one of those strings causes the system to 14Writing to this file one of those strings causes the system to
diff --git a/Documentation/power/states.txt b/Documentation/power/states.txt
index 4416b28630df..42f28b7aaf6b 100644
--- a/Documentation/power/states.txt
+++ b/Documentation/power/states.txt
@@ -2,12 +2,26 @@
2System Power Management States 2System Power Management States
3 3
4 4
5The kernel supports three power management states generically, though 5The kernel supports four power management states generically, though
6each is dependent on platform support code to implement the low-level 6one is generic and the other three are dependent on platform support
7details for each state. This file describes each state, what they are 7code to implement the low-level details for each state.
8This file describes each state, what they are
8commonly called, what ACPI state they map to, and what string to write 9commonly called, what ACPI state they map to, and what string to write
9to /sys/power/state to enter that state 10to /sys/power/state to enter that state
10 11
12state: Freeze / Low-Power Idle
13ACPI state: S0
14String: "freeze"
15
16This state is a generic, pure software, light-weight, low-power state.
17It allows more energy to be saved relative to idle by freezing user
18space and putting all I/O devices into low-power states (possibly
19lower-power than available at run time), such that the processors can
20spend more time in their idle states.
21This state can be used for platforms without Standby/Suspend-to-RAM
22support, or it can be used in addition to Suspend-to-RAM (memory sleep)
23to provide reduced resume latency.
24
11 25
12State: Standby / Power-On Suspend 26State: Standby / Power-On Suspend
13ACPI State: S1 27ACPI State: S1