# SPDX-License-Identifier: GPL-2.0-onlyconfig SUSPEND	bool "Suspend to RAM and standby"	depends on ARCH_SUSPEND_POSSIBLE	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 ACPI S3 state). config SUSPEND_FREEZER	bool "Enable freezer for suspend to RAM/standby" \		if ARCH_WANTS_FREEZER_CONTROL || BROKEN	depends on SUSPEND	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 SUSPEND_SKIP_SYNC	bool "Skip kernel's sys_sync() on suspend to RAM/standby"	depends on SUSPEND	depends on EXPERT	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.  There's a run-time switch	  at '/sys/power/sync_on_suspend' to configure this behaviour.	  This setting changes the default for the run-tim switch. Say Y	  to change the default to disable the kernel sys_sync(). config HIBERNATE_CALLBACKS	bool config HIBERNATION	bool "Hibernation (aka 'suspend to disk')"	depends on SWAP && ARCH_HIBERNATION_POSSIBLE	select HIBERNATE_CALLBACKS	select CRC32	select CRYPTO	select CRYPTO_LZO	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 ACPI or APM, although for example	  ACPI 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 HIBERNATION_SNAPSHOT_DEV	bool "Userspace snapshot device"	depends on HIBERNATION	default y	help	  Device used by the uswsusp tools. 	  Say N if no snapshotting from userspace is needed, this also	  reduces the attack surface of the kernel. 	  If in doubt, say Y. choice	prompt "Default compressor"	default HIBERNATION_COMP_LZO	depends on HIBERNATION config HIBERNATION_COMP_LZO	bool "lzo"	depends on CRYPTO_LZO config HIBERNATION_COMP_LZ4	bool "lz4"	depends on CRYPTO_LZ4 endchoice config HIBERNATION_DEF_COMP	string	default "lzo" if HIBERNATION_COMP_LZO	default "lz4" if HIBERNATION_COMP_LZ4	help	  Default compressor to be used for hibernation. config PM_STD_PARTITION	string "Default resume partition"	depends on HIBERNATION	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 PM_SLEEP	def_bool y	depends on SUSPEND || HIBERNATE_CALLBACKS	select PM config PM_SLEEP_SMP	def_bool y	depends on SMP	depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE	depends on PM_SLEEP	select HOTPLUG_CPU config PM_SLEEP_SMP_NONZERO_CPU	def_bool y	depends on PM_SLEEP_SMP	depends on ARCH_SUSPEND_NONZERO_CPU	help	If an arch can suspend (for suspend, hibernate, kexec, etc) on a	non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This	will allow nohz_full mask to include CPU0. config PM_AUTOSLEEP	bool "Opportunistic sleep"	depends on PM_SLEEP	help	Allow the kernel to trigger a system transition into a global sleep	state automatically whenever there are no active wakeup sources. config PM_USERSPACE_AUTOSLEEP	bool "Userspace opportunistic sleep"	depends on PM_SLEEP	help	Notify kernel of aggressive userspace autosleep power management policy. 	This option changes the behavior of various sleep-sensitive code to deal	with frequent userspace-initiated transitions into a global sleep state. 	Saying Y here, disables code paths that most users really should keep	enabled. In particular, only enable this if it is very common to be	asleep/awake for very short periods of time (<= 2 seconds). 	Only platforms, such as Android, that implement opportunistic sleep from	a userspace power manager service should enable this option; and not	other machines. Therefore, you should say N here, unless you are	extremely certain that this is what you want. The option otherwise has	bad, undesirable effects, and should not be enabled just for fun.  config PM_WAKELOCKS	bool "User space wakeup sources interface"	depends on PM_SLEEP	help	Allow user space to create, activate and deactivate wakeup source	objects with the help of a sysfs-based interface. config PM_WAKELOCKS_LIMIT	int "Maximum number of user space wakeup sources (0 = no limit)"	range 0 100000	default 100	depends on PM_WAKELOCKS config PM_WAKELOCKS_GC	bool "Garbage collector for user space wakeup sources"	depends on PM_WAKELOCKS	default y config PM	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 PM_DEBUG	bool "Power Management Debug Support"	depends on PM	help	This option enables various debugging support in the Power Management	code. This is helpful when debugging and reporting PM bugs, like	suspend support. config PM_ADVANCED_DEBUG	bool "Extra PM attributes in sysfs for low-level debugging/testing"	depends on PM_DEBUG	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 PM_TEST_SUSPEND	bool "Test suspend/resume and wakealarm during bootup"	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y	help	This option will let you suspend your machine during bootup, and	make it wake up a few seconds later using an RTC wakeup alarm.	Enable this with a kernel parameter like "test_suspend=mem". 	You probably want to have your system's RTC driver statically	linked, ensuring that it's available when this test runs. config PM_SLEEP_DEBUG	def_bool y	depends on PM_DEBUG && PM_SLEEP config DPM_WATCHDOG	bool "Device suspend/resume watchdog"	depends on PM_DEBUG && PSTORE && EXPERT	help	  Sets up a watchdog timer to capture drivers that are	  locked up attempting to suspend/resume a device.	  A detected lockup causes system panic with message	  captured in pstore device for inspection in subsequent	  boot session. config DPM_WATCHDOG_TIMEOUT	int "Watchdog timeout in seconds"	range 1 120	default 120	depends on DPM_WATCHDOG config PM_TRACE	bool	help	  This enables code to save the last PM event point across	  reboot. The architecture needs to support this, x86 for	  example does by saving things in the RTC, 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 PM_TRACE_RTC	bool "Suspend/resume event tracing"	depends on PM_SLEEP_DEBUG	depends on X86	select PM_TRACE	help	This enables some cheesy code to save the last PM event point in the	RTC 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 APM_EMULATION	tristate "Advanced Power Management Emulation"	depends on SYS_SUPPORTS_APM_EMULATION	help	  APM is a BIOS specification for saving power using several different	  techniques. This is mostly useful for battery powered laptops with	  APM 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 APM "events" (e.g. battery status change). 	  In order to use APM, 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	  APM in your BIOS). config PM_CLK	def_bool y	depends on PM && HAVE_CLK config PM_GENERIC_DOMAINS	bool	depends on PM config WQ_POWER_EFFICIENT_DEFAULT	bool "Enable workqueue power-efficient mode by default"	depends on PM	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 PM_GENERIC_DOMAINS_SLEEP	def_bool y	depends on PM_SLEEP && PM_GENERIC_DOMAINS config PM_GENERIC_DOMAINS_OF	def_bool y	depends on PM_GENERIC_DOMAINS && OF config CPU_PM	bool config ENERGY_MODEL	bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)"	depends on SMP	depends on CPU_FREQ	help	  Several subsystems (thermal and/or the task scheduler for example)	  can leverage information about the energy consumed by devices 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.