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_RUNTIME
 107         bool "Run-time PM core functionality"
 108         depends on !IA64_HP_SIM
 109         ---help---
 110           Enable functionality allowing I/O devices to be put into energy-saving
 111           (low power) states at run time (or autosuspended) after a specified
 112           period of inactivity and woken up in response to a hardware-generated
 113           wake-up event or a driver's request.
 114
 115           Hardware support is generally required for this functionality to work
 116           and the bus type drivers of the buses the devices are on are
 117           responsible for the actual handling of the autosuspend requests and
 118           wake-up events.
 119
 120 config PM
 121         def_bool y
 122         depends on PM_SLEEP || PM_RUNTIME
 123
 124 config PM_DEBUG
 125         bool "Power Management Debug Support"
 126         depends on PM
 127         ---help---
 128         This option enables various debugging support in the Power Management
 129         code. This is helpful when debugging and reporting PM bugs, like
 130         suspend support.
 131
 132 config PM_ADVANCED_DEBUG
 133         bool "Extra PM attributes in sysfs for low-level debugging/testing"
 134         depends on PM_DEBUG
 135         ---help---
 136         Add extra sysfs attributes allowing one to access some Power Management
 137         fields of device objects from user space.  If you are not a kernel
 138         developer interested in debugging/testing Power Management, say "no".
 139
 140 config PM_TEST_SUSPEND
 141         bool "Test suspend/resume and wakealarm during bootup"
 142         depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
 143         ---help---
 144         This option will let you suspend your machine during bootup, and
 145         make it wake up a few seconds later using an RTC wakeup alarm.
 146         Enable this with a kernel parameter like "test_suspend=mem".
 147
 148         You probably want to have your system's RTC driver statically
 149         linked, ensuring that it's available when this test runs.
 150
 151 config CAN_PM_TRACE
 152         def_bool y
 153         depends on PM_DEBUG && PM_SLEEP
 154
 155 config PM_TRACE
 156         bool
 157         help
 158           This enables code to save the last PM event point across
 159           reboot. The architecture needs to support this, x86 for
 160           example does by saving things in the RTC, see below.
 161
 162           The architecture specific code must provide the extern
 163           functions from <linux/resume-trace.h> as well as the
 164           <asm/resume-trace.h> header with a TRACE_RESUME() macro.
 165
 166           The way the information is presented is architecture-
 167           dependent, x86 will print the information during a
 168           late_initcall.
 169
 170 config PM_TRACE_RTC
 171         bool "Suspend/resume event tracing"
 172         depends on CAN_PM_TRACE
 173         depends on X86
 174         select PM_TRACE
 175         ---help---
 176         This enables some cheesy code to save the last PM event point in the
 177         RTC across reboots, so that you can debug a machine that just hangs
 178         during suspend (or more commonly, during resume).
 179
 180         To use this debugging feature you should attempt to suspend the
 181         machine, reboot it and then run
 182
 183                 dmesg -s 1000000 | grep 'hash matches'
 184
 185         CAUTION: this option will cause your machine's real-time clock to be
 186         set to an invalid time after a resume.
 187
 188 config APM_EMULATION
 189         tristate "Advanced Power Management Emulation"
 190         depends on PM && SYS_SUPPORTS_APM_EMULATION
 191         help
 192           APM is a BIOS specification for saving power using several different
 193           techniques. This is mostly useful for battery powered laptops with
 194           APM compliant BIOSes. If you say Y here, the system time will be
 195           reset after a RESUME operation, the /proc/apm device will provide
 196           battery status information, and user-space programs will receive
 197           notification of APM "events" (e.g. battery status change).
 198
 199           In order to use APM, you will need supporting software. For location
 200           and more information, read <file:Documentation/power/apm-acpi.txt>
 201           and the Battery Powered Linux mini-HOWTO, available from
 202           <http://www.tldp.org/docs.html#howto>.
 203
 204           This driver does not spin down disk drives (see the hdparm(8)
 205           manpage ("man 8 hdparm") for that), and it doesn't turn off
 206           VESA-compliant "green" monitors.
 207
 208           Generally, if you don't have a battery in your machine, there isn't
 209           much point in using this driver and you should say N. If you get
 210           random kernel OOPSes or reboots that don't seem to be related to
 211           anything, try disabling/enabling this option (or disabling/enabling
 212           APM in your BIOS).
 213
 214 config ARCH_HAS_OPP
 215         bool
 216
 217 config PM_OPP
 218         bool "Operating Performance Point (OPP) Layer library"
 219         depends on ARCH_HAS_OPP
 220         ---help---
 221           SOCs have a standard set of tuples consisting of frequency and
 222           voltage pairs that the device will support per voltage domain. This
 223           is called Operating Performance Point or OPP. The actual definitions
 224           of OPP varies over silicon within the same family of devices.
 225
 226           OPP layer organizes the data internally using device pointers
 227           representing individual voltage domains and provides SOC
 228           implementations a ready to use framework to manage OPPs.
 229           For more information, read <file:Documentation/power/opp.txt>
 230
 231 config PM_CLK
 232         def_bool y
 233         depends on PM && HAVE_CLK
 234
 235 config PM_GENERIC_DOMAINS
 236         bool
 237         depends on PM
 238
 239 config PM_GENERIC_DOMAINS_RUNTIME
 240         def_bool y
 241         depends on PM_RUNTIME && PM_GENERIC_DOMAINS
 242
 243 config CPU_PM
 244         bool
 245         depends on SUSPEND || CPU_IDLE