path: root/kernel/power/Kconfig

config 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 HIBERNATE_CALLBACKS
	bool

config HIBERNATION
	bool "Hibernation (aka 'suspend to disk')"
	depends on SWAP && ARCH_HIBERNATION_POSSIBLE
	select HIBERNATE_CALLBACKS
	select LZO_COMPRESS
	select LZO_DECOMPRESS
	select CRC32
	---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.txt>).

	  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.txt>.

config ARCH_SAVE_PAGE_KEYS
	bool

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.

menuconfig TOI_CORE
	bool "Enhanced Hibernation (TuxOnIce)"
	depends on HIBERNATION
	default y
	---help---
	  TuxOnIce is the 'new and improved' suspend support.

	  See the TuxOnIce home page (tuxonice.net)
	  for FAQs, HOWTOs and other documentation.

	comment "Image Storage (you need at least one allocator)"
		depends on TOI_CORE

	config TOI_FILE
		bool "File Allocator"
		depends on TOI_CORE
		default y
		---help---
		  This option enables support for storing an image in a
		  simple file. You might want this if your swap is
		  sometimes full enough that you don't have enough spare
		  space to store an image.

	config TOI_SWAP
		bool "Swap Allocator"
		depends on TOI_CORE && SWAP
		default y
		---help---
		  This option enables support for storing an image in your
		  swap space.

	comment "General Options"
		depends on TOI_CORE

	config TOI_PRUNE
		bool "Image pruning support"
		depends on TOI_CORE && CRYPTO && BROKEN
		default y
		---help---
		  This option adds support for using cryptoapi hashing
		  algorithms to identify pages with the same content. We
		  then write a much smaller pointer to the first copy of
		  the data instead of a complete (perhaps compressed)
                  additional copy.

		  You probably want this, so say Y here.

	comment "No image pruning support available without Cryptoapi support."
		depends on TOI_CORE && !CRYPTO

	config TOI_CRYPTO
		bool "Compression support"
		depends on TOI_CORE && CRYPTO
		default y
		---help---
		  This option adds support for using cryptoapi compression
		  algorithms. Compression is particularly useful as it can
		  more than double your suspend and resume speed (depending
		  upon how well your image compresses).

		  You probably want this, so say Y here.

	comment "No compression support available without Cryptoapi support."
		depends on TOI_CORE && !CRYPTO

	config TOI_USERUI
		bool "Userspace User Interface support"
		depends on TOI_CORE && NET && (VT || SERIAL_CONSOLE)
		default y
		---help---
		  This option enabled support for a userspace based user interface
		  to TuxOnIce, which allows you to have a nice display while suspending
		  and resuming, and also enables features such as pressing escape to
		  cancel a cycle or interactive debugging.

	config TOI_USERUI_DEFAULT_PATH
		string "Default userui program location"
		default "/usr/local/sbin/tuxoniceui_text"
		depends on TOI_USERUI
		---help---
		  This entry allows you to specify a default path to the userui binary.

	config TOI_DEFAULT_IMAGE_SIZE_LIMIT
		int "Default image size limit"
		range -2 65536 
		default "-2"
		depends on TOI_CORE
		---help---
		  This entry allows you to specify a default image size limit. It can
		  be overridden at run-time using /sys/power/tuxonice/image_size_limit.

	config TOI_KEEP_IMAGE
		bool "Allow Keep Image Mode"
		depends on TOI_CORE
		---help---
		  This option allows you to keep and image and reuse it. It is intended
		  __ONLY__ for use with systems where all filesystems are mounted read-
		  only (kiosks, for example). To use it, compile this option in and boot
		  normally. Set the KEEP_IMAGE flag in /sys/power/tuxonice and suspend.
		  When you resume, the image will not be removed. You will be unable to turn
		  off swap partitions (assuming you are using the swap allocator), but future
		  suspends simply do a power-down. The image can be updated using the
		  kernel command line parameter suspend_act= to turn off the keep image
		  bit. Keep image mode is a little less user friendly on purpose - it
		  should not be used without thought!

	config TOI_INCREMENTAL
		bool "Incremental Image Support"
		depends on TOI_CORE && 64BIT && TOI_KEEP_IMAGE
		default n
		---help---
		  This option enables the work in progress toward using the dirty page
		  tracking to record changes to pages. It is hoped that
		  this will be an initial step toward implementing storing just
		  the differences between consecutive images, which will
		  increase the amount of storage needed for the image, but also
		  increase the speed at which writing an image occurs and
		  reduce the wear and tear on drives.

		  At the moment, all that is implemented is the first step of keeping
		  an existing image and then comparing it to the contents in memory
		  (by setting /sys/power/tuxonice/verify_image to 1 and triggering a
		  (fake) resume) to see what the page change tracking should find to be
		  different. If you have verify_image set to 1, TuxOnIce will automatically
		  invalidate the old image when you next try to hibernate, so there's no
		  greater chance of disk corruption than normal.

	comment "No incremental image support available without Keep Image support."
		depends on TOI_CORE && !TOI_KEEP_IMAGE && 64BIT

	config TOI_REPLACE_SWSUSP
		bool "Replace swsusp by default"
		default y
		depends on TOI_CORE
		---help---
		  TuxOnIce can replace swsusp. This option makes that the default state,
		  requiring you to echo 0 > /sys/power/tuxonice/replace_swsusp if you want
		  to use the vanilla kernel functionality. Note that your initrd/ramfs will
		  need to do this before trying to resume, too.
		  With overriding swsusp enabled, echoing disk  to /sys/power/state will
		  start a TuxOnIce cycle. If resume= doesn't specify an allocator and both
		  the swap and file allocators are compiled in, the swap allocator will be
		  used by default.

	config TOI_IGNORE_LATE_INITCALL
		bool "Wait for initrd/ramfs to run, by default"
		default n
		depends on TOI_CORE
		---help---
		  When booting, TuxOnIce can check for an image and start to resume prior
		  to any initrd/ramfs running (via a late initcall).

		  If you don't have an initrd/ramfs, this is what you want to happen -
		  otherwise you won't be able to safely resume. You should set this option
		  to 'No'.

		  If, however, you want your initrd/ramfs to run anyway before resuming,
		  you need to tell TuxOnIce to ignore that earlier opportunity to resume.
		  This can be done either by using this compile time option, or by
		  overriding this option with the boot-time parameter toi_initramfs_resume_only=1.

		  Note that if TuxOnIce can't resume at the earlier opportunity, the
		  value of this option won't matter - the initramfs/initrd (if any) will
		  run anyway.

	menuconfig TOI_CLUSTER
		bool "Cluster support"
		default n
		depends on TOI_CORE && NET && BROKEN
		---help---
		  Support for linking multiple machines in a cluster so that they suspend
		  and resume together.

	config TOI_DEFAULT_CLUSTER_INTERFACE
		string "Default cluster interface"
		depends on TOI_CLUSTER
		---help---
		  The default interface on which to communicate with other nodes in
		  the cluster.

		  If no value is set here, cluster support will be disabled by default.

	config TOI_DEFAULT_CLUSTER_KEY
		string "Default cluster key"
		default "Default"
		depends on TOI_CLUSTER
		---help---
		  The default key used by this node. All nodes in the same cluster
		  have the same key. Multiple clusters may coexist on the same lan
		  by using different values for this key.

	config TOI_CLUSTER_IMAGE_TIMEOUT
		int "Timeout when checking for image"
		default 15
		depends on TOI_CLUSTER
		---help---
		  Timeout (seconds) before continuing to boot when waiting to see
		  whether other nodes might have an image. Set to -1 to wait
		  indefinitely. In WAIT_UNTIL_NODES is non zero, we might continue
		  booting sooner than this timeout.

	config TOI_CLUSTER_WAIT_UNTIL_NODES
		int "Nodes without image before continuing"
		default 0
		depends on TOI_CLUSTER
		---help---
		  When booting and no image is found, we wait to see if other nodes
		  have an image before continuing to boot. This value lets us
		  continue after seeing a certain number of nodes without an image,
		  instead of continuing to wait for the timeout. Set to 0 to only
		  use the timeout.

	config TOI_DEFAULT_CLUSTER_PRE_HIBERNATE
		string "Default pre-hibernate script"
		depends on TOI_CLUSTER
		---help---
		  The default script to be called when starting to hibernate.

	config TOI_DEFAULT_CLUSTER_POST_HIBERNATE
		string "Default post-hibernate script"
		depends on TOI_CLUSTER
		---help---
		  The default script to be called after resuming from hibernation.

	config TOI_DEFAULT_WAIT
		int "Default waiting time for emergency boot messages"
		default "25"
		range -1 32768
		depends on TOI_CORE
		help
		  TuxOnIce can display warnings very early in the process of resuming,
		  if (for example) it appears that you have booted a kernel that doesn't
		  match an image on disk. It can then give you the opportunity to either
		  continue booting that kernel, or reboot the machine. This option can be
		  used to control how long to wait in such circumstances. -1 means wait
		  forever. 0 means don't wait at all (do the default action, which will
		  generally be to continue booting and remove the image). Values of 1 or
		  more indicate a number of seconds (up to 255) to wait before doing the
		  default.

	config  TOI_DEFAULT_EXTRA_PAGES_ALLOWANCE
		int "Default extra pages allowance"
		default "2000"
		range 500 32768
		depends on TOI_CORE
		help
		  This value controls the default for the allowance TuxOnIce makes for
		  drivers to allocate extra memory during the atomic copy. The default
		  value of 2000 will be okay in most cases. If you are using
		  DRI, the easiest way to find what value to use is to try to hibernate
		  and look at how many pages were actually needed in the sysfs entry
		  /sys/power/tuxonice/debug_info (first number on the last line), adding
		  a little extra because the value is not always the same.

	config TOI_CHECKSUM
		bool "Checksum pageset2"
		default n
		depends on TOI_CORE
		select CRYPTO
		select CRYPTO_ALGAPI
		select CRYPTO_MD4
		---help---
		  Adds support for checksumming pageset2 pages, to ensure you really get an
		  atomic copy. Since some filesystems (XFS especially) change metadata even
		  when there's no other activity, we need this to check for pages that have
		  been changed while we were saving the page cache. If your debugging output
		  always says no pages were resaved, you may be able to safely disable this
		  option.

config TOI
	bool
	depends on TOI_CORE!=n
	default y

config TOI_ZRAM_SUPPORT
	def_bool y
	depends on TOI && ZRAM!=n

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_AUTOSLEEP
	bool "Opportunistic sleep"
	depends on PM_SLEEP
	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 PM_WAKELOCKS
	bool "User space wakeup sources interface"
	depends on PM_SLEEP
	default n
	---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
	---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 60
	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 PM && 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.txt>
	  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_OPP
	bool
	select SRCU
	---help---
	  SOCs have a standard set of tuples consisting of frequency and
	  voltage pairs that the device will support per voltage domain. This
	  is called Operating Performance Point or OPP. The actual definitions
	  of OPP varies over silicon within the same family of devices.

	  OPP layer organizes the data internally using device pointers
	  representing individual voltage domains and provides SOC
	  implementations a ready to use framework to manage OPPs.
	  For more information, read <file:Documentation/power/opp.txt>

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
	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 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