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-rw-r--r--Documentation/ABI/testing/sysfs-power67
1 files changed, 57 insertions, 10 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 6f87b9dd384b..a3942b1036e2 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -47,14 +47,18 @@ Description:
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.
@@ -74,12 +78,12 @@ 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.
@@ -114,9 +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
@@ -148,7 +152,7 @@ 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
@@ -244,6 +248,7 @@ Description:
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.
@@ -290,7 +295,7 @@ Description:
What: /sys/power/resume_offset
Date: April 2018
-Contact: Mario Limonciello <mario.limonciello@dell.com>
+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.
@@ -407,3 +412,45 @@ 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.