| 1 | # SPDX-License-Identifier: GPL-2.0-only |
| 2 | config SUSPEND |
| 3 | bool "Suspend to RAM and standby" |
| 4 | depends on ARCH_SUSPEND_POSSIBLE |
| 5 | default y |
| 6 | help |
| 7 | Allow the system to enter sleep states in which main memory is |
| 8 | powered and thus its contents are preserved, such as the |
| 9 | suspend-to-RAM state (e.g. the ACPI S3 state). |
| 10 | |
| 11 | config SUSPEND_FREEZER |
| 12 | bool "Enable freezer for suspend to RAM/standby" \ |
| 13 | if ARCH_WANTS_FREEZER_CONTROL || BROKEN |
| 14 | depends on SUSPEND |
| 15 | default y |
| 16 | help |
| 17 | This allows you to turn off the freezer for suspend. If this is |
| 18 | done, no tasks are frozen for suspend to RAM/standby. |
| 19 | |
| 20 | Turning OFF this setting is NOT recommended! If in doubt, say Y. |
| 21 | |
| 22 | config SUSPEND_SKIP_SYNC |
| 23 | bool "Skip kernel's sys_sync() on suspend to RAM/standby" |
| 24 | depends on SUSPEND |
| 25 | depends on EXPERT |
| 26 | help |
| 27 | Skip the kernel sys_sync() before freezing user processes. |
| 28 | Some systems prefer not to pay this cost on every invocation |
| 29 | of suspend, or they are content with invoking sync() from |
| 30 | user-space before invoking suspend. There's a run-time switch |
| 31 | at '/sys/power/sync_on_suspend' to configure this behaviour. |
| 32 | This setting changes the default for the run-tim switch. Say Y |
| 33 | to change the default to disable the kernel sys_sync(). |
| 34 | |
| 35 | config HIBERNATE_CALLBACKS |
| 36 | bool |
| 37 | |
| 38 | config HIBERNATION |
| 39 | bool "Hibernation (aka 'suspend to disk')" |
| 40 | depends on SWAP && ARCH_HIBERNATION_POSSIBLE |
| 41 | select HIBERNATE_CALLBACKS |
| 42 | select CRC32 |
| 43 | select CRYPTO |
| 44 | select CRYPTO_LZO |
| 45 | select CRYPTO_LZ4 |
| 46 | help |
| 47 | Enable the suspend to disk (STD) functionality, which is usually |
| 48 | called "hibernation" in user interfaces. STD checkpoints the |
| 49 | system and powers it off; and restores that checkpoint on reboot. |
| 50 | |
| 51 | You can suspend your machine with 'echo disk > /sys/power/state' |
| 52 | after placing resume=/dev/swappartition on the kernel command line |
| 53 | in your bootloader's configuration file. |
| 54 | |
| 55 | Alternatively, you can use the additional userland tools available |
| 56 | from <http://suspend.sf.net>. |
| 57 | |
| 58 | In principle it does not require ACPI or APM, although for example |
| 59 | ACPI will be used for the final steps when it is available. One |
| 60 | of the reasons to use software suspend is that the firmware hooks |
| 61 | for suspend states like suspend-to-RAM (STR) often don't work very |
| 62 | well with Linux. |
| 63 | |
| 64 | It creates an image which is saved in your active swap. Upon the next |
| 65 | boot, pass the 'resume=/dev/swappartition' argument to the kernel to |
| 66 | have it detect the saved image, restore memory state from it, and |
| 67 | continue to run as before. If you do not want the previous state to |
| 68 | be reloaded, then use the 'noresume' kernel command line argument. |
| 69 | Note, however, that fsck will be run on your filesystems and you will |
| 70 | need to run mkswap against the swap partition used for the suspend. |
| 71 | |
| 72 | It also works with swap files to a limited extent (for details see |
| 73 | <file:Documentation/power/swsusp-and-swap-files.rst>). |
| 74 | |
| 75 | Right now you may boot without resuming and resume later but in the |
| 76 | meantime you cannot use the swap partition(s)/file(s) involved in |
| 77 | suspending. Also in this case you must not use the filesystems |
| 78 | that were mounted before the suspend. In particular, you MUST NOT |
| 79 | MOUNT any journaled filesystems mounted before the suspend or they |
| 80 | will get corrupted in a nasty way. |
| 81 | |
| 82 | For more information take a look at <file:Documentation/power/swsusp.rst>. |
| 83 | |
| 84 | config HIBERNATION_SNAPSHOT_DEV |
| 85 | bool "Userspace snapshot device" |
| 86 | depends on HIBERNATION |
| 87 | default y |
| 88 | help |
| 89 | Device used by the uswsusp tools. |
| 90 | |
| 91 | Say N if no snapshotting from userspace is needed, this also |
| 92 | reduces the attack surface of the kernel. |
| 93 | |
| 94 | If in doubt, say Y. |
| 95 | |
| 96 | choice |
| 97 | prompt "Default compressor" |
| 98 | default HIBERNATION_COMP_LZO |
| 99 | depends on HIBERNATION |
| 100 | |
| 101 | config HIBERNATION_COMP_LZO |
| 102 | bool "lzo" |
| 103 | depends on CRYPTO_LZO |
| 104 | |
| 105 | config HIBERNATION_COMP_LZ4 |
| 106 | bool "lz4" |
| 107 | depends on CRYPTO_LZ4 |
| 108 | |
| 109 | endchoice |
| 110 | |
| 111 | config HIBERNATION_DEF_COMP |
| 112 | string |
| 113 | default "lzo" if HIBERNATION_COMP_LZO |
| 114 | default "lz4" if HIBERNATION_COMP_LZ4 |
| 115 | help |
| 116 | Default compressor to be used for hibernation. |
| 117 | |
| 118 | config PM_STD_PARTITION |
| 119 | string "Default resume partition" |
| 120 | depends on HIBERNATION |
| 121 | default "" |
| 122 | help |
| 123 | The default resume partition is the partition that the suspend- |
| 124 | to-disk implementation will look for a suspended disk image. |
| 125 | |
| 126 | The partition specified here will be different for almost every user. |
| 127 | It should be a valid swap partition (at least for now) that is turned |
| 128 | on before suspending. |
| 129 | |
| 130 | The partition specified can be overridden by specifying: |
| 131 | |
| 132 | resume=/dev/<other device> |
| 133 | |
| 134 | which will set the resume partition to the device specified. |
| 135 | |
| 136 | Note there is currently not a way to specify which device to save the |
| 137 | suspended image to. It will simply pick the first available swap |
| 138 | device. |
| 139 | |
| 140 | config PM_SLEEP |
| 141 | def_bool y |
| 142 | depends on SUSPEND || HIBERNATE_CALLBACKS |
| 143 | select PM |
| 144 | |
| 145 | config PM_SLEEP_SMP |
| 146 | def_bool y |
| 147 | depends on SMP |
| 148 | depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE |
| 149 | depends on PM_SLEEP |
| 150 | select HOTPLUG_CPU |
| 151 | |
| 152 | config PM_SLEEP_SMP_NONZERO_CPU |
| 153 | def_bool y |
| 154 | depends on PM_SLEEP_SMP |
| 155 | depends on ARCH_SUSPEND_NONZERO_CPU |
| 156 | help |
| 157 | If an arch can suspend (for suspend, hibernate, kexec, etc) on a |
| 158 | non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This |
| 159 | will allow nohz_full mask to include CPU0. |
| 160 | |
| 161 | config PM_AUTOSLEEP |
| 162 | bool "Opportunistic sleep" |
| 163 | depends on PM_SLEEP |
| 164 | help |
| 165 | Allow the kernel to trigger a system transition into a global sleep |
| 166 | state automatically whenever there are no active wakeup sources. |
| 167 | |
| 168 | config PM_USERSPACE_AUTOSLEEP |
| 169 | bool "Userspace opportunistic sleep" |
| 170 | depends on PM_SLEEP |
| 171 | help |
| 172 | Notify kernel of aggressive userspace autosleep power management policy. |
| 173 | |
| 174 | This option changes the behavior of various sleep-sensitive code to deal |
| 175 | with frequent userspace-initiated transitions into a global sleep state. |
| 176 | |
| 177 | Saying Y here, disables code paths that most users really should keep |
| 178 | enabled. In particular, only enable this if it is very common to be |
| 179 | asleep/awake for very short periods of time (<= 2 seconds). |
| 180 | |
| 181 | Only platforms, such as Android, that implement opportunistic sleep from |
| 182 | a userspace power manager service should enable this option; and not |
| 183 | other machines. Therefore, you should say N here, unless you are |
| 184 | extremely certain that this is what you want. The option otherwise has |
| 185 | bad, undesirable effects, and should not be enabled just for fun. |
| 186 | |
| 187 | |
| 188 | config PM_WAKELOCKS |
| 189 | bool "User space wakeup sources interface" |
| 190 | depends on PM_SLEEP |
| 191 | help |
| 192 | Allow user space to create, activate and deactivate wakeup source |
| 193 | objects with the help of a sysfs-based interface. |
| 194 | |
| 195 | config PM_WAKELOCKS_LIMIT |
| 196 | int "Maximum number of user space wakeup sources (0 = no limit)" |
| 197 | range 0 100000 |
| 198 | default 100 |
| 199 | depends on PM_WAKELOCKS |
| 200 | |
| 201 | config PM_WAKELOCKS_GC |
| 202 | bool "Garbage collector for user space wakeup sources" |
| 203 | depends on PM_WAKELOCKS |
| 204 | default y |
| 205 | |
| 206 | config PM_QOS_CPU_SYSTEM_WAKEUP |
| 207 | bool "User space interface for CPU system wakeup QoS" |
| 208 | depends on CPU_IDLE |
| 209 | help |
| 210 | Enable this to allow user space via the cpu_wakeup_latency file to |
| 211 | specify a CPU system wakeup latency limit. |
| 212 | |
| 213 | This may be particularly useful for platforms supporting multiple low |
| 214 | power states for CPUs during system-wide suspend and s2idle in |
| 215 | particular. |
| 216 | |
| 217 | config PM |
| 218 | bool "Device power management core functionality" |
| 219 | help |
| 220 | Enable functionality allowing I/O devices to be put into energy-saving |
| 221 | (low power) states, for example after a specified period of inactivity |
| 222 | (autosuspended), and woken up in response to a hardware-generated |
| 223 | wake-up event or a driver's request. |
| 224 | |
| 225 | Hardware support is generally required for this functionality to work |
| 226 | and the bus type drivers of the buses the devices are on are |
| 227 | responsible for the actual handling of device suspend requests and |
| 228 | wake-up events. |
| 229 | |
| 230 | config PM_DEBUG |
| 231 | bool "Power Management Debug Support" |
| 232 | depends on PM |
| 233 | help |
| 234 | This option enables various debugging support in the Power Management |
| 235 | code. This is helpful when debugging and reporting PM bugs, like |
| 236 | suspend support. |
| 237 | |
| 238 | config PM_ADVANCED_DEBUG |
| 239 | bool "Extra PM attributes in sysfs for low-level debugging/testing" |
| 240 | depends on PM_DEBUG |
| 241 | help |
| 242 | Add extra sysfs attributes allowing one to access some Power Management |
| 243 | fields of device objects from user space. If you are not a kernel |
| 244 | developer interested in debugging/testing Power Management, say "no". |
| 245 | |
| 246 | config PM_TEST_SUSPEND |
| 247 | bool "Test suspend/resume and wakealarm during bootup" |
| 248 | depends on SUSPEND && PM_DEBUG && RTC_CLASS=y |
| 249 | help |
| 250 | This option will let you suspend your machine during bootup, and |
| 251 | make it wake up a few seconds later using an RTC wakeup alarm. |
| 252 | Enable this with a kernel parameter like "test_suspend=mem". |
| 253 | |
| 254 | You probably want to have your system's RTC driver statically |
| 255 | linked, ensuring that it's available when this test runs. |
| 256 | |
| 257 | config PM_SLEEP_DEBUG |
| 258 | def_bool y |
| 259 | depends on PM_DEBUG && PM_SLEEP |
| 260 | |
| 261 | config DPM_WATCHDOG |
| 262 | bool "Device suspend/resume watchdog" |
| 263 | depends on PM_DEBUG && PSTORE && EXPERT |
| 264 | help |
| 265 | Sets up a watchdog timer to capture drivers that are |
| 266 | locked up attempting to suspend/resume a device. |
| 267 | A detected lockup causes system panic with message |
| 268 | captured in pstore device for inspection in subsequent |
| 269 | boot session. |
| 270 | |
| 271 | config DPM_WATCHDOG_ENABLED |
| 272 | bool "Enable DPM watchdog by default" |
| 273 | depends on DPM_WATCHDOG |
| 274 | default y |
| 275 | help |
| 276 | If you say Y here, the DPM watchdog will be enabled by default. |
| 277 | If you say N, it will be compiled in but disabled. It can be |
| 278 | enabled at boot time via the "pm.dpm_watchdog_enabled" kernel |
| 279 | parameter or at runtime via sysfs. |
| 280 | |
| 281 | config DPM_WATCHDOG_TIMEOUT |
| 282 | int "Watchdog timeout to panic in seconds" |
| 283 | range 1 120 |
| 284 | default 120 |
| 285 | depends on DPM_WATCHDOG |
| 286 | |
| 287 | config DPM_WATCHDOG_WARNING_TIMEOUT |
| 288 | int "Watchdog timeout to warn in seconds" |
| 289 | range 1 DPM_WATCHDOG_TIMEOUT |
| 290 | default DPM_WATCHDOG_TIMEOUT |
| 291 | depends on DPM_WATCHDOG |
| 292 | help |
| 293 | If the DPM watchdog warning timeout and main timeout are |
| 294 | different then a non-fatal warning (with a stack trace of |
| 295 | the stuck suspend routine) will be printed when the warning |
| 296 | timeout expires. If the suspend routine gets un-stuck |
| 297 | before the main timeout expires then no other action is |
| 298 | taken. If the routine continues to be stuck and the main |
| 299 | timeout expires then an emergency-level message and stack |
| 300 | trace will be printed and the system will panic. |
| 301 | |
| 302 | If the warning timeout is equal to the main timeout (the |
| 303 | default) then the warning will never happen and the system |
| 304 | will jump straight to panic when the main timeout expires. |
| 305 | |
| 306 | config PM_TRACE |
| 307 | bool |
| 308 | help |
| 309 | This enables code to save the last PM event point across |
| 310 | reboot. The architecture needs to support this, x86 for |
| 311 | example does by saving things in the RTC, see below. |
| 312 | |
| 313 | The architecture specific code must provide the extern |
| 314 | functions from <linux/resume-trace.h> as well as the |
| 315 | <asm/resume-trace.h> header with a TRACE_RESUME() macro. |
| 316 | |
| 317 | The way the information is presented is architecture- |
| 318 | dependent, x86 will print the information during a |
| 319 | late_initcall. |
| 320 | |
| 321 | config PM_TRACE_RTC |
| 322 | bool "Suspend/resume event tracing" |
| 323 | depends on PM_SLEEP_DEBUG |
| 324 | depends on X86 |
| 325 | select PM_TRACE |
| 326 | help |
| 327 | This enables some cheesy code to save the last PM event point in the |
| 328 | RTC across reboots, so that you can debug a machine that just hangs |
| 329 | during suspend (or more commonly, during resume). |
| 330 | |
| 331 | To use this debugging feature you should attempt to suspend the |
| 332 | machine, reboot it and then run |
| 333 | |
| 334 | dmesg -s 1000000 | grep 'hash matches' |
| 335 | |
| 336 | CAUTION: this option will cause your machine's real-time clock to be |
| 337 | set to an invalid time after a resume. |
| 338 | |
| 339 | config APM_EMULATION |
| 340 | tristate "Advanced Power Management Emulation" |
| 341 | depends on SYS_SUPPORTS_APM_EMULATION |
| 342 | help |
| 343 | APM is a BIOS specification for saving power using several different |
| 344 | techniques. This is mostly useful for battery powered laptops with |
| 345 | APM compliant BIOSes. If you say Y here, the system time will be |
| 346 | reset after a RESUME operation, the /proc/apm device will provide |
| 347 | battery status information, and user-space programs will receive |
| 348 | notification of APM "events" (e.g. battery status change). |
| 349 | |
| 350 | In order to use APM, you will need supporting software. For location |
| 351 | and more information, read <file:Documentation/power/apm-acpi.rst> |
| 352 | and the Battery Powered Linux mini-HOWTO, available from |
| 353 | <http://www.tldp.org/docs.html#howto>. |
| 354 | |
| 355 | This driver does not spin down disk drives (see the hdparm(8) |
| 356 | manpage ("man 8 hdparm") for that), and it doesn't turn off |
| 357 | VESA-compliant "green" monitors. |
| 358 | |
| 359 | Generally, if you don't have a battery in your machine, there isn't |
| 360 | much point in using this driver and you should say N. If you get |
| 361 | random kernel OOPSes or reboots that don't seem to be related to |
| 362 | anything, try disabling/enabling this option (or disabling/enabling |
| 363 | APM in your BIOS). |
| 364 | |
| 365 | config PM_CLK |
| 366 | def_bool y |
| 367 | depends on PM && HAVE_CLK |
| 368 | |
| 369 | config PM_GENERIC_DOMAINS |
| 370 | bool |
| 371 | depends on PM |
| 372 | |
| 373 | config WQ_POWER_EFFICIENT_DEFAULT |
| 374 | bool "Enable workqueue power-efficient mode by default" |
| 375 | depends on PM |
| 376 | help |
| 377 | Per-cpu workqueues are generally preferred because they show |
| 378 | better performance thanks to cache locality; unfortunately, |
| 379 | per-cpu workqueues tend to be more power hungry than unbound |
| 380 | workqueues. |
| 381 | |
| 382 | Enabling workqueue.power_efficient kernel parameter makes the |
| 383 | per-cpu workqueues which were observed to contribute |
| 384 | significantly to power consumption unbound, leading to measurably |
| 385 | lower power usage at the cost of small performance overhead. |
| 386 | |
| 387 | This config option determines whether workqueue.power_efficient |
| 388 | is enabled by default. |
| 389 | |
| 390 | If in doubt, say N. |
| 391 | |
| 392 | config PM_GENERIC_DOMAINS_SLEEP |
| 393 | def_bool y |
| 394 | depends on PM_SLEEP && PM_GENERIC_DOMAINS |
| 395 | |
| 396 | config PM_GENERIC_DOMAINS_OF |
| 397 | def_bool y |
| 398 | depends on PM_GENERIC_DOMAINS && OF |
| 399 | |
| 400 | config CPU_PM |
| 401 | bool |
| 402 | |
| 403 | config ENERGY_MODEL |
| 404 | bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)" |
| 405 | depends on CPU_FREQ || PM_DEVFREQ |
| 406 | help |
| 407 | Several subsystems (thermal and/or the task scheduler for example) |
| 408 | can leverage information about the energy consumed by devices to |
| 409 | make smarter decisions. This config option enables the framework |
| 410 | from which subsystems can access the energy models. |
| 411 | |
| 412 | The exact usage of the energy model is subsystem-dependent. |
| 413 | |
| 414 | If in doubt, say N. |