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