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-rw-r--r--Documentation/ABI/testing/sysfs-power290
1 files changed, 258 insertions, 32 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 217772615d02..d38da077905a 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -1,41 +1,64 @@
What: /sys/power/
Date: August 2006
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+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: August 2006
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+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/state file controls the system power state.
- Reading from this file returns what states are supported,
- which is hard-coded to 'standby' (Power-On Suspend), 'mem'
- (Suspend-to-RAM), and 'disk' (Suspend-to-Disk).
+ 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.
- Writing to this file one of these strings causes the system to
- transition into that state. Please see the file
- Documentation/power/states.txt for a description of each of
- these states.
+ See Documentation/admin-guide/pm/sleep-states.rst for more
+ information.
What: /sys/power/disk
Date: September 2006
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+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.
@@ -55,19 +78,19 @@ Description:
The suspend-to-disk method may be chosen by writing to this
file one of the accepted strings:
- 'firmware'
- 'platform'
- 'shutdown'
- 'reboot'
- 'testproc'
- 'test'
+ - 'firmware'
+ - 'platform'
+ - 'shutdown'
+ - 'reboot'
+ - 'testproc'
+ - 'test'
It will only change to 'firmware' or 'platform' if the system
supports that.
What: /sys/power/image_size
Date: August 2006
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/image_size file controls the size of the image
created by the suspend-to-disk mechanism. It can be written a
@@ -80,11 +103,11 @@ Description:
this file, the suspend image will be as small as possible.
Reading from this file will display the current image size
- limit, which is set to 500 MB by default.
+ limit, which is set to around 2/5 of available RAM by default.
What: /sys/power/pm_trace
Date: August 2006
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/pm_trace file controls the code which saves the
last PM event point in the RTC across reboots, so that you can
@@ -95,9 +118,9 @@ Description:
string representing a nonzero integer into it.
To use this debugging feature you should attempt to suspend
- the machine, then reboot it and run
+ the machine, then reboot it and run::
- dmesg -s 1000000 | grep 'hash matches'
+ dmesg -s 1000000 | grep 'hash matches'
If you do not get any matches (or they appear to be false
positives), it is possible that the last PM event point
@@ -108,9 +131,9 @@ Description:
CAUTION: Using it will cause your machine's real-time (CMOS)
clock to be set to a random invalid time after a resume.
-What; /sys/power/pm_trace_dev_match
+What: /sys/power/pm_trace_dev_match
Date: October 2010
-Contact: James Hogan <james@albanarts.com>
+Contact: James Hogan <jhogan@kernel.org>
Description:
The /sys/power/pm_trace_dev_match file contains the name of the
device associated with the last PM event point saved in the RTC
@@ -129,11 +152,11 @@ Description:
case further investigation is required to determine which
device is causing the problem. Note that genuine RTC clock
values (such as when pm_trace has not been used), can still
- match a device and output it's name here.
+ match a device and output its name here.
What: /sys/power/pm_async
Date: January 2009
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/pm_async file controls the switch allowing the
user space to enable or disable asynchronous suspend and resume
@@ -146,7 +169,7 @@ Description:
What: /sys/power/wakeup_count
Date: July 2010
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/wakeup_count file allows user space to put the
system into a sleep state while taking into account the
@@ -161,7 +184,7 @@ Description:
What: /sys/power/reserved_size
Date: May 2011
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/reserved_size file allows user space to control
the amount of memory reserved for allocations made by device
@@ -175,7 +198,7 @@ Description:
What: /sys/power/autosleep
Date: April 2012
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/autosleep file can be written one of the strings
returned by reads from /sys/power/state. If that happens, a
@@ -192,7 +215,7 @@ Description:
What: /sys/power/wake_lock
Date: February 2012
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/wake_lock file allows user space to create
wakeup source objects and activate them on demand (if one of
@@ -219,12 +242,13 @@ Description:
What: /sys/power/wake_unlock
Date: February 2012
-Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Contact: Rafael J. Wysocki <rafael@kernel.org>
Description:
The /sys/power/wake_unlock file allows user space to deactivate
wakeup sources created with the help of /sys/power/wake_lock.
When a string is written to /sys/power/wake_unlock, it will be
assumed to represent the name of a wakeup source to deactivate.
+
If a wakeup source object of that name exists and is active at
the moment, it will be deactivated.
@@ -244,3 +268,205 @@ Description:
Writing a "1" enables this printing while writing a "0"
disables it. The default value is "0". Reading from this file
will display the current value.
+
+What: /sys/power/pm_wakeup_irq
+Date: April 2015
+Contact: Alexandra Yates <alexandra.yates@linux.intel.org>
+Description:
+ The /sys/power/pm_wakeup_irq file reports to user space the IRQ
+ number of the first wakeup interrupt (that is, the first
+ interrupt from an IRQ line armed for system wakeup) seen by the
+ kernel during the most recent system suspend/resume cycle.
+
+ This output is useful for system wakeup diagnostics of spurious
+ wakeup interrupts.
+
+What: /sys/power/pm_debug_messages
+Date: July 2017
+Contact: Rafael J. Wysocki <rafael@kernel.org>
+Description:
+ The /sys/power/pm_debug_messages file controls the printing
+ of debug messages from the system suspend/hiberbation
+ infrastructure to the kernel log.
+
+ Writing a "1" to this file enables the debug messages and
+ writing a "0" (default) to it disables them. Reads from
+ this file return the current value.
+
+What: /sys/power/resume_offset
+Date: April 2018
+Contact: Mario Limonciello <mario.limonciello@outlook.com>
+Description:
+ This file is used for telling the kernel an offset into a disk
+ to use when hibernating the system such as with a swap file.
+
+ Reads from this file will display the current offset
+ the kernel will be using on the next hibernation
+ attempt.
+
+ Using this sysfs file will override any values that were
+ set using the kernel command line for disk offset.
+
+What: /sys/power/suspend_stats
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats directory contains suspend related
+ statistics.
+
+What: /sys/power/suspend_stats/success
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/success file contains the number
+ of times entering system sleep state succeeded.
+
+What: /sys/power/suspend_stats/fail
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/fail file contains the number
+ of times entering system sleep state failed.
+
+What: /sys/power/suspend_stats/failed_freeze
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_freeze file contains the
+ number of times freezing processes failed.
+
+What: /sys/power/suspend_stats/failed_prepare
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_prepare file contains the
+ number of times preparing all non-sysdev devices for
+ a system PM transition failed.
+
+What: /sys/power/suspend_stats/failed_resume
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_resume file contains the
+ number of times executing "resume" callbacks of
+ non-sysdev devices failed.
+
+What: /sys/power/suspend_stats/failed_resume_early
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_resume_early file contains
+ the number of times executing "early resume" callbacks
+ of devices failed.
+
+What: /sys/power/suspend_stats/failed_resume_noirq
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_resume_noirq file contains
+ the number of times executing "noirq resume" callbacks
+ of devices failed.
+
+What: /sys/power/suspend_stats/failed_suspend
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_suspend file contains
+ the number of times executing "suspend" callbacks
+ of all non-sysdev devices failed.
+
+What: /sys/power/suspend_stats/failed_suspend_late
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_suspend_late file contains
+ the number of times executing "late suspend" callbacks
+ of all devices failed.
+
+What: /sys/power/suspend_stats/failed_suspend_noirq
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/failed_suspend_noirq file contains
+ the number of times executing "noirq suspend" callbacks
+ of all devices failed.
+
+What: /sys/power/suspend_stats/last_failed_dev
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/last_failed_dev file contains
+ the last device for which a suspend/resume callback failed.
+
+What: /sys/power/suspend_stats/last_failed_errno
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/last_failed_errno file contains
+ the errno of the last failed attempt at entering
+ system sleep state.
+
+What: /sys/power/suspend_stats/last_failed_step
+Date: July 2019
+Contact: Kalesh Singh <kaleshsingh96@gmail.com>
+Description:
+ The /sys/power/suspend_stats/last_failed_step file contains
+ the last failed step in the suspend/resume path.
+
+What: /sys/power/suspend_stats/last_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/last_hw_sleep file
+ contains the duration of time spent in a hardware sleep
+ state in the most recent system suspend-resume cycle.
+ This number is measured in microseconds.
+
+What: /sys/power/suspend_stats/total_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/total_hw_sleep file
+ contains the aggregate of time spent in a hardware sleep
+ state since the kernel was booted. This number
+ is measured in microseconds.
+
+What: /sys/power/suspend_stats/max_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/max_hw_sleep file
+ contains the maximum amount of time that the hardware can
+ report for time spent in a hardware sleep state. When sleep
+ cycles are longer than this time, the values for
+ 'total_hw_sleep' and 'last_hw_sleep' may not be accurate.
+ This number is measured in microseconds.
+
+What: /sys/power/sync_on_suspend
+Date: October 2019
+Contact: Jonas Meurer <jonas@freesources.org>
+Description:
+ This file controls whether or not the kernel will sync()
+ filesystems during system suspend (after freezing user space
+ and before suspending devices).
+
+ Writing a "1" to this file enables the sync() and writing a "0"
+ disables it. Reads from the file return the current value.
+ The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config
+ flag is unset, or "0" otherwise.
+
+What: /sys/power/hibernate_compression_threads
+Date: October 2025
+Contact: <luoxueqin@kylinos.cn>
+Description:
+ Controls the number of threads used for compression
+ and decompression of hibernation images.
+
+ The value can be adjusted at runtime to balance
+ performance and CPU utilization.
+
+ The change takes effect on the next hibernation or
+ resume operation.
+
+ Minimum value: 1
+ Default value: 3