kernel/power/Kconfig

   1 config SUSPEND
   2         bool "Suspend to RAM and standby"
   3         depends on ARCH_SUSPEND_POSSIBLE
   4         default y
   5         ---help---
   6           Allow the system to enter sleep states in which main memory is
   7           powered and thus its contents are preserved, such as the
   8           suspend-to-RAM state (e.g. the ACPI S3 state).
   9
  10 config SUSPEND_FREEZER
  11         bool "Enable freezer for suspend to RAM/standby" \
  12                 if ARCH_WANTS_FREEZER_CONTROL || BROKEN
  13         depends on SUSPEND
  14         default y
  15         help
  16           This allows you to turn off the freezer for suspend. If this is
  17           done, no tasks are frozen for suspend to RAM/standby.
  18
  19           Turning OFF this setting is NOT recommended! If in doubt, say Y.
  20
  21 config HAS_WAKELOCK
  22         bool
  23         default y
  24
  25 config WAKELOCK
  26         bool
  27         default y
  28
  29 config HIBERNATE_CALLBACKS
  30         bool
  31
  32 config HIBERNATION
  33         bool "Hibernation (aka 'suspend to disk')"
  34         depends on SWAP && ARCH_HIBERNATION_POSSIBLE
  35         select HIBERNATE_CALLBACKS
  36         select LZO_COMPRESS
  37         select LZO_DECOMPRESS
  38         select CRC32
  39         ---help---
  40           Enable the suspend to disk (STD) functionality, which is usually
  41           called "hibernation" in user interfaces.  STD checkpoints the
  42           system and powers it off; and restores that checkpoint on reboot.
  43
  44           You can suspend your machine with 'echo disk > /sys/power/state'
  45           after placing resume=/dev/swappartition on the kernel command line
  46           in your bootloader's configuration file.
  47
  48           Alternatively, you can use the additional userland tools available
  49           from <http://suspend.sf.net>.
  50
  51           In principle it does not require ACPI or APM, although for example
  52           ACPI will be used for the final steps when it is available.  One
  53           of the reasons to use software suspend is that the firmware hooks
  54           for suspend states like suspend-to-RAM (STR) often don't work very
  55           well with Linux.
  56
  57           It creates an image which is saved in your active swap. Upon the next
  58           boot, pass the 'resume=/dev/swappartition' argument to the kernel to
  59           have it detect the saved image, restore memory state from it, and
  60           continue to run as before. If you do not want the previous state to
  61           be reloaded, then use the 'noresume' kernel command line argument.
  62           Note, however, that fsck will be run on your filesystems and you will
  63           need to run mkswap against the swap partition used for the suspend.
  64
  65           It also works with swap files to a limited extent (for details see
  66           <file:Documentation/power/swsusp-and-swap-files.txt>).
  67
  68           Right now you may boot without resuming and resume later but in the
  69           meantime you cannot use the swap partition(s)/file(s) involved in
  70           suspending.  Also in this case you must not use the filesystems
  71           that were mounted before the suspend.  In particular, you MUST NOT
  72           MOUNT any journaled filesystems mounted before the suspend or they
  73           will get corrupted in a nasty way.
  74
  75           For more information take a look at <file:Documentation/power/swsusp.txt>.
  76
  77 config ARCH_SAVE_PAGE_KEYS
  78         bool
  79
  80 config PM_STD_PARTITION
  81         string "Default resume partition"
  82         depends on HIBERNATION
  83         default ""
  84         ---help---
  85           The default resume partition is the partition that the suspend-
  86           to-disk implementation will look for a suspended disk image.
  87
  88           The partition specified here will be different for almost every user.
  89           It should be a valid swap partition (at least for now) that is turned
  90           on before suspending.
  91
  92           The partition specified can be overridden by specifying:
  93
  94                 resume=/dev/<other device>
  95
  96           which will set the resume partition to the device specified.
  97
  98           Note there is currently not a way to specify which device to save the
  99           suspended image to. It will simply pick the first available swap
 100           device.
 101
 102 config PM_SLEEP
 103         def_bool y
 104         depends on SUSPEND || HIBERNATE_CALLBACKS
 105
 106 config PM_SLEEP_SMP
 107         def_bool y
 108         depends on SMP
 109         depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
 110         depends on PM_SLEEP
 111         select HOTPLUG
 112         select HOTPLUG_CPU
 113
 114 config PM_AUTOSLEEP
 115         bool "Opportunistic sleep"
 116         depends on PM_SLEEP
 117         default n
 118         ---help---
 119         Allow the kernel to trigger a system transition into a global sleep
 120         state automatically whenever there are no active wakeup sources.
 121
 122 config PM_WAKELOCKS
 123         bool "User space wakeup sources interface"
 124         depends on PM_SLEEP
 125         default n
 126         ---help---
 127         Allow user space to create, activate and deactivate wakeup source
 128         objects with the help of a sysfs-based interface.
 129
 130 config PM_WAKELOCKS_LIMIT
 131         int "Maximum number of user space wakeup sources (0 = no limit)"
 132         range 0 100000
 133         default 100
 134         depends on PM_WAKELOCKS
 135
 136 config PM_WAKELOCKS_GC
 137         bool "Garbage collector for user space wakeup sources"
 138         depends on PM_WAKELOCKS
 139         default y
 140
 141 config PM_RUNTIME
 142         bool "Run-time PM core functionality"
 143         depends on !IA64_HP_SIM
 144         ---help---
 145           Enable functionality allowing I/O devices to be put into energy-saving
 146           (low power) states at run time (or autosuspended) after a specified
 147           period of inactivity and woken up in response to a hardware-generated
 148           wake-up event or a driver's request.
 149
 150           Hardware support is generally required for this functionality to work
 151           and the bus type drivers of the buses the devices are on are
 152           responsible for the actual handling of the autosuspend requests and
 153           wake-up events.
 154
 155 config PM_RUNTIME_TEST_SYSFS
 156         bool "Runtime PM test interface in sysfs" if PM_RUNTIME
 157         depends on SYSFS
 158         ---help---
 159           Enable sysfs interface for RUNTIME PM test. /sys/class/runtime_pm/test/
 160           is created. When you read the file "control" you can get the active
 161           power domain in Exynos. When you write power domain name you can test
 162           the power domain.
 163
 164 config PM_DOMAIN_DEBUG
 165         bool "Runtime PM debug message" if PM_RUNTIME
 166
 167 config PM
 168         def_bool y
 169         depends on PM_SLEEP || PM_RUNTIME
 170
 171 config PM_DEBUG
 172         bool "Power Management Debug Support"
 173         depends on PM
 174         ---help---
 175         This option enables various debugging support in the Power Management
 176         code. This is helpful when debugging and reporting PM bugs, like
 177         suspend support.
 178
 179 config PM_ADVANCED_DEBUG
 180         bool "Extra PM attributes in sysfs for low-level debugging/testing"
 181         depends on PM_DEBUG
 182         ---help---
 183         Add extra sysfs attributes allowing one to access some Power Management
 184         fields of device objects from user space.  If you are not a kernel
 185         developer interested in debugging/testing Power Management, say "no".
 186
 187 config PM_TEST_SUSPEND
 188         bool "Test suspend/resume and wakealarm during bootup"
 189         depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
 190         ---help---
 191         This option will let you suspend your machine during bootup, and
 192         make it wake up a few seconds later using an RTC wakeup alarm.
 193         Enable this with a kernel parameter like "test_suspend=mem".
 194
 195         You probably want to have your system's RTC driver statically
 196         linked, ensuring that it's available when this test runs.
 197
 198 config PM_SLEEP_DEBUG
 199         def_bool y
 200         depends on PM_DEBUG && PM_SLEEP
 201
 202 config PM_TRACE
 203         bool
 204         help
 205           This enables code to save the last PM event point across
 206           reboot. The architecture needs to support this, x86 for
 207           example does by saving things in the RTC, see below.
 208
 209           The architecture specific code must provide the extern
 210           functions from <linux/resume-trace.h> as well as the
 211           <asm/resume-trace.h> header with a TRACE_RESUME() macro.
 212
 213           The way the information is presented is architecture-
 214           dependent, x86 will print the information during a
 215           late_initcall.
 216
 217 config PM_TRACE_RTC
 218         bool "Suspend/resume event tracing"
 219         depends on PM_SLEEP_DEBUG
 220         depends on X86
 221         select PM_TRACE
 222         ---help---
 223         This enables some cheesy code to save the last PM event point in the
 224         RTC across reboots, so that you can debug a machine that just hangs
 225         during suspend (or more commonly, during resume).
 226
 227         To use this debugging feature you should attempt to suspend the
 228         machine, reboot it and then run
 229
 230                 dmesg -s 1000000 | grep 'hash matches'
 231
 232         CAUTION: this option will cause your machine's real-time clock to be
 233         set to an invalid time after a resume.
 234
 235 config APM_EMULATION
 236         tristate "Advanced Power Management Emulation"
 237         depends on PM && SYS_SUPPORTS_APM_EMULATION
 238         help
 239           APM is a BIOS specification for saving power using several different
 240           techniques. This is mostly useful for battery powered laptops with
 241           APM compliant BIOSes. If you say Y here, the system time will be
 242           reset after a RESUME operation, the /proc/apm device will provide
 243           battery status information, and user-space programs will receive
 244           notification of APM "events" (e.g. battery status change).
 245
 246           In order to use APM, you will need supporting software. For location
 247           and more information, read <file:Documentation/power/apm-acpi.txt>
 248           and the Battery Powered Linux mini-HOWTO, available from
 249           <http://www.tldp.org/docs.html#howto>.
 250
 251           This driver does not spin down disk drives (see the hdparm(8)
 252           manpage ("man 8 hdparm") for that), and it doesn't turn off
 253           VESA-compliant "green" monitors.
 254
 255           Generally, if you don't have a battery in your machine, there isn't
 256           much point in using this driver and you should say N. If you get
 257           random kernel OOPSes or reboots that don't seem to be related to
 258           anything, try disabling/enabling this option (or disabling/enabling
 259           APM in your BIOS).
 260
 261 config ARCH_HAS_OPP
 262         bool
 263
 264 config PM_OPP
 265         bool "Operating Performance Point (OPP) Layer library"
 266         depends on ARCH_HAS_OPP
 267         ---help---
 268           SOCs have a standard set of tuples consisting of frequency and
 269           voltage pairs that the device will support per voltage domain. This
 270           is called Operating Performance Point or OPP. The actual definitions
 271           of OPP varies over silicon within the same family of devices.
 272
 273           OPP layer organizes the data internally using device pointers
 274           representing individual voltage domains and provides SOC
 275           implementations a ready to use framework to manage OPPs.
 276           For more information, read <file:Documentation/power/opp.txt>
 277
 278 config PM_CLK
 279         def_bool y
 280         depends on PM && HAVE_CLK
 281
 282 config PM_GENERIC_DOMAINS
 283         bool
 284         depends on PM
 285
 286 config WQ_POWER_EFFICIENT_DEFAULT
 287         bool "Enable workqueue power-efficient mode by default"
 288         depends on PM
 289         default n
 290         help
 291           Per-cpu workqueues are generally preferred because they show
 292           better performance thanks to cache locality; unfortunately,
 293           per-cpu workqueues tend to be more power hungry than unbound
 294           workqueues.
 295
 296           Enabling workqueue.power_efficient kernel parameter makes the
 297           per-cpu workqueues which were observed to contribute
 298           significantly to power consumption unbound, leading to measurably
 299           lower power usage at the cost of small performance overhead.
 300
 301           This config option determines whether workqueue.power_efficient
 302           is enabled by default.
 303
 304           If in doubt, say N.
 305
 306 config PM_GENERIC_DOMAINS_SLEEP
 307         def_bool y
 308         depends on PM_SLEEP && PM_GENERIC_DOMAINS
 309
 310 config PM_GENERIC_DOMAINS_RUNTIME
 311         def_bool y
 312         depends on PM_RUNTIME && PM_GENERIC_DOMAINS
 313
 314 config CPU_PM
 315         bool
 316         depends on SUSPEND || CPU_IDLE
 317
 318 config SUSPEND_TIME
 319         bool "Log time spent in suspend"
 320         ---help---
 321           Prints the time spent in suspend in the kernel log, and
 322           keeps statistics on the time spent in suspend in
 323           /sys/kernel/debug/suspend_time