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