# SPDX-License-Identifier: GPL-2.0-only
config [31mCONFIG_SUSPEND[0m
bool "Suspend to RAM and standby"
depends on [31mCONFIG_ARCH_SUSPEND_POSSIBLE[0m
default y
---help---
Allow the system to enter sleep states in which main memory is
powered and thus its contents are preserved, such as the
suspend-to-RAM state (e.g. the [31mCONFIG_ACPI[0m S3 state).
config [31mCONFIG_SUSPEND_FREEZER[0m
bool "Enable freezer for suspend to RAM/standby" \
if [31mCONFIG_ARCH_WANTS_FREEZER_CONTROL[0m || [31mCONFIG_BROKEN[0m
depends on [31mCONFIG_SUSPEND[0m
default y
help
This allows you to turn off the freezer for suspend. If this is
done, no tasks are frozen for suspend to RAM/standby.
Turning OFF this setting is NOT recommended! If in doubt, say Y.
config [31mCONFIG_SUSPEND_SKIP_SYNC[0m
bool "Skip kernel's sys_sync() on suspend to RAM/standby"
depends on [31mCONFIG_SUSPEND[0m
depends on [31mCONFIG_EXPERT[0m
help
Skip the kernel sys_sync() before freezing user processes.
Some systems prefer not to pay this cost on every invocation
of suspend, or they are content with invoking sync() from
user-space before invoking suspend. Say Y if that's your case.
config [31mCONFIG_HIBERNATE_CALLBACKS[0m
bool
config [31mCONFIG_HIBERNATION[0m
bool "Hibernation (aka 'suspend to disk')"
depends on [31mCONFIG_SWAP[0m && [31mCONFIG_ARCH_HIBERNATION_POSSIBLE[0m
select [31mCONFIG_HIBERNATE_CALLBACKS[0m
select [31mCONFIG_LZO_COMPRESS[0m
select [31mCONFIG_LZO_DECOMPRESS[0m
select [31mCONFIG_CRC32[0m
---help---
Enable the suspend to disk (STD) functionality, which is usually
called "hibernation" in user interfaces. STD checkpoints the
system and powers it off; and restores that checkpoint on reboot.
You can suspend your machine with 'echo disk > /sys/power/state'
after placing resume=/dev/swappartition on the kernel command line
in your bootloader's configuration file.
Alternatively, you can use the additional userland tools available
from <http://suspend.sf.net>.
In principle it does not require [31mCONFIG_ACPI[0m or [31mCONFIG_APM[0m, although for example
[31mCONFIG_ACPI[0m will be used for the final steps when it is available. One
of the reasons to use software suspend is that the firmware hooks
for suspend states like suspend-to-RAM (STR) often don't work very
well with Linux.
It creates an image which is saved in your active swap. Upon the next
boot, pass the 'resume=/dev/swappartition' argument to the kernel to
have it detect the saved image, restore memory state from it, and
continue to run as before. If you do not want the previous state to
be reloaded, then use the 'noresume' kernel command line argument.
Note, however, that fsck will be run on your filesystems and you will
need to run mkswap against the swap partition used for the suspend.
It also works with swap files to a limited extent (for details see
<file:Documentation/power/swsusp-and-swap-files.rst>).
Right now you may boot without resuming and resume later but in the
meantime you cannot use the swap partition(s)/file(s) involved in
suspending. Also in this case you must not use the filesystems
that were mounted before the suspend. In particular, you MUST NOT
MOUNT any journaled filesystems mounted before the suspend or they
will get corrupted in a nasty way.
For more information take a look at <file:Documentation/power/swsusp.rst>.
config [31mCONFIG_ARCH_SAVE_PAGE_KEYS[0m
bool
config [31mCONFIG_PM_STD_PARTITION[0m
string "Default resume partition"
depends on [31mCONFIG_HIBERNATION[0m
default ""
---help---
The default resume partition is the partition that the suspend-
to-disk implementation will look for a suspended disk image.
The partition specified here will be different for almost every user.
It should be a valid swap partition (at least for now) that is turned
on before suspending.
The partition specified can be overridden by specifying:
resume=/dev/<other device>
which will set the resume partition to the device specified.
Note there is currently not a way to specify which device to save the
suspended image to. It will simply pick the first available swap
device.
config [31mCONFIG_PM_SLEEP[0m
def_bool y
depends on [31mCONFIG_SUSPEND[0m || [31mCONFIG_HIBERNATE_CALLBACKS[0m
select [31mCONFIG_PM[0m
select [31mCONFIG_SRCU[0m
config [31mCONFIG_PM_SLEEP_SMP[0m
def_bool y
depends on [31mCONFIG_SMP[0m
depends on [31mCONFIG_ARCH_SUSPEND_POSSIBLE[0m || [31mCONFIG_ARCH_HIBERNATION_POSSIBLE[0m
depends on [31mCONFIG_PM_SLEEP[0m
select [31mCONFIG_HOTPLUG_CPU[0m
config [31mCONFIG_PM_SLEEP_SMP_NONZERO_CPU[0m
def_bool y
depends on [31mCONFIG_PM_SLEEP_SMP[0m
depends on [31mCONFIG_ARCH_SUSPEND_NONZERO_CPU[0m
---help---
If an arch can suspend (for suspend, hibernate, kexec, etc) on a
non-zero numbered CPU, it may define [31mCONFIG_ARCH_SUSPEND_NONZERO_CPU[0m. This
will allow nohz_full mask to include CPU0.
config [31mCONFIG_PM_AUTOSLEEP[0m
bool "Opportunistic sleep"
depends on [31mCONFIG_PM_SLEEP[0m
default n
---help---
Allow the kernel to trigger a system transition into a global sleep
state automatically whenever there are no active wakeup sources.
config [31mCONFIG_PM_WAKELOCKS[0m
bool "User space wakeup sources interface"
depends on [31mCONFIG_PM_SLEEP[0m
default n
---help---
Allow user space to create, activate and deactivate wakeup source
objects with the help of a sysfs-based interface.
config [31mCONFIG_PM_WAKELOCKS_LIMIT[0m
int "Maximum number of user space wakeup sources (0 = no limit)"
range 0 100000
default 100
depends on [31mCONFIG_PM_WAKELOCKS[0m
config [31mCONFIG_PM_WAKELOCKS_GC[0m
bool "Garbage collector for user space wakeup sources"
depends on [31mCONFIG_PM_WAKELOCKS[0m
default y
config [31mCONFIG_PM[0m
bool "Device power management core functionality"
---help---
Enable functionality allowing I/O devices to be put into energy-saving
(low power) states, for example after a specified period of inactivity
(autosuspended), and woken up in response to a hardware-generated
wake-up event or a driver's request.
Hardware support is generally required for this functionality to work
and the bus type drivers of the buses the devices are on are
responsible for the actual handling of device suspend requests and
wake-up events.
config [31mCONFIG_PM_DEBUG[0m
bool "Power Management Debug Support"
depends on [31mCONFIG_PM[0m
---help---
This option enables various debugging support in the Power Management
code. This is helpful when debugging and reporting [31mCONFIG_PM[0m bugs, like
suspend support.
config [31mCONFIG_PM_ADVANCED_DEBUG[0m
bool "Extra PM attributes in sysfs for low-level debugging/testing"
depends on [31mCONFIG_PM_DEBUG[0m
---help---
Add extra sysfs attributes allowing one to access some Power Management
fields of device objects from user space. If you are not a kernel
developer interested in debugging/testing Power Management, say "no".
config [31mCONFIG_PM_TEST_SUSPEND[0m
bool "Test suspend/resume and wakealarm during bootup"
depends on [31mCONFIG_SUSPEND[0m && [31mCONFIG_PM_DEBUG[0m && [31mCONFIG_RTC_CLASS[0m=y
---help---
This option will let you suspend your machine during bootup, and
make it wake up a few seconds later using an [31mCONFIG_RTC[0m wakeup alarm.
Enable this with a kernel parameter like "test_suspend=mem".
You probably want to have your system's [31mCONFIG_RTC[0m driver statically
linked, ensuring that it's available when this test runs.
config [31mCONFIG_PM_SLEEP_DEBUG[0m
def_bool y
depends on [31mCONFIG_PM_DEBUG[0m && [31mCONFIG_PM_SLEEP[0m
config [31mCONFIG_DPM_WATCHDOG[0m
bool "Device suspend/resume watchdog"
depends on [31mCONFIG_PM_DEBUG[0m && [31mCONFIG_PSTORE[0m && [31mCONFIG_EXPERT[0m
---help---
Sets up a watchdog timer to capture drivers that are
locked up attempting to suspend/resume a device.
[31mCONFIG_A[0m detected lockup causes system panic with message
captured in pstore device for inspection in subsequent
boot session.
config [31mCONFIG_DPM_WATCHDOG_TIMEOUT[0m
int "Watchdog timeout in seconds"
range 1 120
default 120
depends on [31mCONFIG_DPM_WATCHDOG[0m
config [31mCONFIG_PM_TRACE[0m
bool
help
This enables code to save the last [31mCONFIG_PM[0m event point across
reboot. The architecture needs to support this, x86 for
example does by saving things in the [31mCONFIG_RTC[0m, see below.
The architecture specific code must provide the extern
functions from <linux/resume-trace.h> as well as the
<asm/resume-trace.h> header with a TRACE_RESUME() macro.
The way the information is presented is architecture-
dependent, x86 will print the information during a
late_initcall.
config [31mCONFIG_PM_TRACE_RTC[0m
bool "Suspend/resume event tracing"
depends on [31mCONFIG_PM_SLEEP_DEBUG[0m
depends on [31mCONFIG_X86[0m
select [31mCONFIG_PM_TRACE[0m
---help---
This enables some cheesy code to save the last [31mCONFIG_PM[0m event point in the
[31mCONFIG_RTC[0m across reboots, so that you can debug a machine that just hangs
during suspend (or more commonly, during resume).
To use this debugging feature you should attempt to suspend the
machine, reboot it and then run
dmesg -s 1000000 | grep 'hash matches'
CAUTION: this option will cause your machine's real-time clock to be
set to an invalid time after a resume.
config [31mCONFIG_APM_EMULATION[0m
tristate "Advanced Power Management Emulation"
depends on [31mCONFIG_SYS_SUPPORTS_APM_EMULATION[0m
help
[31mCONFIG_APM[0m is a BIOS specification for saving power using several different
techniques. This is mostly useful for battery powered laptops with
[31mCONFIG_APM[0m compliant BIOSes. If you say Y here, the system time will be
reset after a RESUME operation, the /proc/apm device will provide
battery status information, and user-space programs will receive
notification of [31mCONFIG_APM[0m "events" (e.g. battery status change).
In order to use [31mCONFIG_APM[0m, you will need supporting software. For location
and more information, read <file:Documentation/power/apm-acpi.rst>
and the Battery Powered Linux mini-HOWTO, available from
<http://www.tldp.org/docs.html#howto>.
This driver does not spin down disk drives (see the hdparm(8)
manpage ("man 8 hdparm") for that), and it doesn't turn off
VESA-compliant "green" monitors.
Generally, if you don't have a battery in your machine, there isn't
much point in using this driver and you should say N. If you get
random kernel OOPSes or reboots that don't seem to be related to
anything, try disabling/enabling this option (or disabling/enabling
[31mCONFIG_APM[0m in your BIOS).
config [31mCONFIG_PM_CLK[0m
def_bool y
depends on [31mCONFIG_PM[0m && [31mCONFIG_HAVE_CLK[0m
config [31mCONFIG_PM_GENERIC_DOMAINS[0m
bool
depends on [31mCONFIG_PM[0m
config [31mCONFIG_WQ_POWER_EFFICIENT_DEFAULT[0m
bool "Enable workqueue power-efficient mode by default"
depends on [31mCONFIG_PM[0m
default n
help
Per-cpu workqueues are generally preferred because they show
better performance thanks to cache locality; unfortunately,
per-cpu workqueues tend to be more power hungry than unbound
workqueues.
Enabling workqueue.power_efficient kernel parameter makes the
per-cpu workqueues which were observed to contribute
significantly to power consumption unbound, leading to measurably
lower power usage at the cost of small performance overhead.
This config option determines whether workqueue.power_efficient
is enabled by default.
If in doubt, say N.
config [31mCONFIG_PM_GENERIC_DOMAINS_SLEEP[0m
def_bool y
depends on [31mCONFIG_PM_SLEEP[0m && [31mCONFIG_PM_GENERIC_DOMAINS[0m
config [31mCONFIG_PM_GENERIC_DOMAINS_OF[0m
def_bool y
depends on [31mCONFIG_PM_GENERIC_DOMAINS[0m && [31mCONFIG_OF[0m
config [31mCONFIG_CPU_PM[0m
bool
config [31mCONFIG_ENERGY_MODEL[0m
bool "Energy Model for CPUs"
depends on [31mCONFIG_SMP[0m
depends on [31mCONFIG_CPU_FREQ[0m
default n
help
Several subsystems (thermal and/or the task scheduler for example)
can leverage information about the energy consumed by CPUs to make
smarter decisions. This config option enables the framework from
which subsystems can access the energy models.
The exact usage of the energy model is subsystem-dependent.
If in doubt, say N.