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