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_SLEEP_SMP_NONZERO_CPU 118 def_bool y 119 depends on PM_SLEEP_SMP 120 depends on ARCH_SUSPEND_NONZERO_CPU 121 ---help--- 122 If an arch can suspend (for suspend, hibernate, kexec, etc) on a 123 non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This 124 will allow nohz_full mask to include CPU0. 125 126config PM_AUTOSLEEP 127 bool "Opportunistic sleep" 128 depends on PM_SLEEP 129 default n 130 ---help--- 131 Allow the kernel to trigger a system transition into a global sleep 132 state automatically whenever there are no active wakeup sources. 133 134config PM_WAKELOCKS 135 bool "User space wakeup sources interface" 136 depends on PM_SLEEP 137 default n 138 ---help--- 139 Allow user space to create, activate and deactivate wakeup source 140 objects with the help of a sysfs-based interface. 141 142config PM_WAKELOCKS_LIMIT 143 int "Maximum number of user space wakeup sources (0 = no limit)" 144 range 0 100000 145 default 100 146 depends on PM_WAKELOCKS 147 148config PM_WAKELOCKS_GC 149 bool "Garbage collector for user space wakeup sources" 150 depends on PM_WAKELOCKS 151 default y 152 153config PM 154 bool "Device power management core functionality" 155 ---help--- 156 Enable functionality allowing I/O devices to be put into energy-saving 157 (low power) states, for example after a specified period of inactivity 158 (autosuspended), and woken up in response to a hardware-generated 159 wake-up event or a driver's request. 160 161 Hardware support is generally required for this functionality to work 162 and the bus type drivers of the buses the devices are on are 163 responsible for the actual handling of device suspend requests and 164 wake-up events. 165 166config PM_DEBUG 167 bool "Power Management Debug Support" 168 depends on PM 169 ---help--- 170 This option enables various debugging support in the Power Management 171 code. This is helpful when debugging and reporting PM bugs, like 172 suspend support. 173 174config PM_ADVANCED_DEBUG 175 bool "Extra PM attributes in sysfs for low-level debugging/testing" 176 depends on PM_DEBUG 177 ---help--- 178 Add extra sysfs attributes allowing one to access some Power Management 179 fields of device objects from user space. If you are not a kernel 180 developer interested in debugging/testing Power Management, say "no". 181 182config PM_TEST_SUSPEND 183 bool "Test suspend/resume and wakealarm during bootup" 184 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y 185 ---help--- 186 This option will let you suspend your machine during bootup, and 187 make it wake up a few seconds later using an RTC wakeup alarm. 188 Enable this with a kernel parameter like "test_suspend=mem". 189 190 You probably want to have your system's RTC driver statically 191 linked, ensuring that it's available when this test runs. 192 193config PM_SLEEP_DEBUG 194 def_bool y 195 depends on PM_DEBUG && PM_SLEEP 196 197config DPM_WATCHDOG 198 bool "Device suspend/resume watchdog" 199 depends on PM_DEBUG && PSTORE && EXPERT 200 ---help--- 201 Sets up a watchdog timer to capture drivers that are 202 locked up attempting to suspend/resume a device. 203 A detected lockup causes system panic with message 204 captured in pstore device for inspection in subsequent 205 boot session. 206 207config DPM_WATCHDOG_TIMEOUT 208 int "Watchdog timeout in seconds" 209 range 1 120 210 default 120 211 depends on DPM_WATCHDOG 212 213config PM_TRACE 214 bool 215 help 216 This enables code to save the last PM event point across 217 reboot. The architecture needs to support this, x86 for 218 example does by saving things in the RTC, see below. 219 220 The architecture specific code must provide the extern 221 functions from <linux/resume-trace.h> as well as the 222 <asm/resume-trace.h> header with a TRACE_RESUME() macro. 223 224 The way the information is presented is architecture- 225 dependent, x86 will print the information during a 226 late_initcall. 227 228config PM_TRACE_RTC 229 bool "Suspend/resume event tracing" 230 depends on PM_SLEEP_DEBUG 231 depends on X86 232 select PM_TRACE 233 ---help--- 234 This enables some cheesy code to save the last PM event point in the 235 RTC across reboots, so that you can debug a machine that just hangs 236 during suspend (or more commonly, during resume). 237 238 To use this debugging feature you should attempt to suspend the 239 machine, reboot it and then run 240 241 dmesg -s 1000000 | grep 'hash matches' 242 243 CAUTION: this option will cause your machine's real-time clock to be 244 set to an invalid time after a resume. 245 246config APM_EMULATION 247 tristate "Advanced Power Management Emulation" 248 depends on SYS_SUPPORTS_APM_EMULATION 249 help 250 APM is a BIOS specification for saving power using several different 251 techniques. This is mostly useful for battery powered laptops with 252 APM compliant BIOSes. If you say Y here, the system time will be 253 reset after a RESUME operation, the /proc/apm device will provide 254 battery status information, and user-space programs will receive 255 notification of APM "events" (e.g. battery status change). 256 257 In order to use APM, you will need supporting software. For location 258 and more information, read <file:Documentation/power/apm-acpi.txt> 259 and the Battery Powered Linux mini-HOWTO, available from 260 <http://www.tldp.org/docs.html#howto>. 261 262 This driver does not spin down disk drives (see the hdparm(8) 263 manpage ("man 8 hdparm") for that), and it doesn't turn off 264 VESA-compliant "green" monitors. 265 266 Generally, if you don't have a battery in your machine, there isn't 267 much point in using this driver and you should say N. If you get 268 random kernel OOPSes or reboots that don't seem to be related to 269 anything, try disabling/enabling this option (or disabling/enabling 270 APM in your BIOS). 271 272config PM_CLK 273 def_bool y 274 depends on PM && HAVE_CLK 275 276config PM_GENERIC_DOMAINS 277 bool 278 depends on PM 279 280config WQ_POWER_EFFICIENT_DEFAULT 281 bool "Enable workqueue power-efficient mode by default" 282 depends on PM 283 default n 284 help 285 Per-cpu workqueues are generally preferred because they show 286 better performance thanks to cache locality; unfortunately, 287 per-cpu workqueues tend to be more power hungry than unbound 288 workqueues. 289 290 Enabling workqueue.power_efficient kernel parameter makes the 291 per-cpu workqueues which were observed to contribute 292 significantly to power consumption unbound, leading to measurably 293 lower power usage at the cost of small performance overhead. 294 295 This config option determines whether workqueue.power_efficient 296 is enabled by default. 297 298 If in doubt, say N. 299 300config PM_GENERIC_DOMAINS_SLEEP 301 def_bool y 302 depends on PM_SLEEP && PM_GENERIC_DOMAINS 303 304config PM_GENERIC_DOMAINS_OF 305 def_bool y 306 depends on PM_GENERIC_DOMAINS && OF 307 308config CPU_PM 309 bool 310 311config ENERGY_MODEL 312 bool "Energy Model for CPUs" 313 depends on SMP 314 depends on CPU_FREQ 315 default n 316 help 317 Several subsystems (thermal and/or the task scheduler for example) 318 can leverage information about the energy consumed by CPUs to make 319 smarter decisions. This config option enables the framework from 320 which subsystems can access the energy models. 321 322 The exact usage of the energy model is subsystem-dependent. 323 324 If in doubt, say N. 325