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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 select SRCU
122
123config PM_SLEEP_SMP
124 def_bool y
125 depends on SMP
126 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
127 depends on PM_SLEEP
128 select HOTPLUG_CPU
129
130config PM_SLEEP_SMP_NONZERO_CPU
131 def_bool y
132 depends on PM_SLEEP_SMP
133 depends on ARCH_SUSPEND_NONZERO_CPU
134 help
135 If an arch can suspend (for suspend, hibernate, kexec, etc) on a
136 non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This
137 will allow nohz_full mask to include CPU0.
138
139config PM_AUTOSLEEP
140 bool "Opportunistic sleep"
141 depends on PM_SLEEP
142 default n
143 help
144 Allow the kernel to trigger a system transition into a global sleep
145 state automatically whenever there are no active wakeup sources.
146
147config PM_WAKELOCKS
148 bool "User space wakeup sources interface"
149 depends on PM_SLEEP
150 default n
151 help
152 Allow user space to create, activate and deactivate wakeup source
153 objects with the help of a sysfs-based interface.
154
155config PM_WAKELOCKS_LIMIT
156 int "Maximum number of user space wakeup sources (0 = no limit)"
157 range 0 100000
158 default 100
159 depends on PM_WAKELOCKS
160
161config PM_WAKELOCKS_GC
162 bool "Garbage collector for user space wakeup sources"
163 depends on PM_WAKELOCKS
164 default y
165
166config PM
167 bool "Device power management core functionality"
168 help
169 Enable functionality allowing I/O devices to be put into energy-saving
170 (low power) states, for example after a specified period of inactivity
171 (autosuspended), and woken up in response to a hardware-generated
172 wake-up event or a driver's request.
173
174 Hardware support is generally required for this functionality to work
175 and the bus type drivers of the buses the devices are on are
176 responsible for the actual handling of device suspend requests and
177 wake-up events.
178
179config PM_DEBUG
180 bool "Power Management Debug Support"
181 depends on PM
182 help
183 This option enables various debugging support in the Power Management
184 code. This is helpful when debugging and reporting PM bugs, like
185 suspend support.
186
187config PM_ADVANCED_DEBUG
188 bool "Extra PM attributes in sysfs for low-level debugging/testing"
189 depends on PM_DEBUG
190 help
191 Add extra sysfs attributes allowing one to access some Power Management
192 fields of device objects from user space. If you are not a kernel
193 developer interested in debugging/testing Power Management, say "no".
194
195config PM_TEST_SUSPEND
196 bool "Test suspend/resume and wakealarm during bootup"
197 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
198 help
199 This option will let you suspend your machine during bootup, and
200 make it wake up a few seconds later using an RTC wakeup alarm.
201 Enable this with a kernel parameter like "test_suspend=mem".
202
203 You probably want to have your system's RTC driver statically
204 linked, ensuring that it's available when this test runs.
205
206config PM_SLEEP_DEBUG
207 def_bool y
208 depends on PM_DEBUG && PM_SLEEP
209
210config DPM_WATCHDOG
211 bool "Device suspend/resume watchdog"
212 depends on PM_DEBUG && PSTORE && EXPERT
213 help
214 Sets up a watchdog timer to capture drivers that are
215 locked up attempting to suspend/resume a device.
216 A detected lockup causes system panic with message
217 captured in pstore device for inspection in subsequent
218 boot session.
219
220config DPM_WATCHDOG_TIMEOUT
221 int "Watchdog timeout in seconds"
222 range 1 120
223 default 120
224 depends on DPM_WATCHDOG
225
226config PM_TRACE
227 bool
228 help
229 This enables code to save the last PM event point across
230 reboot. The architecture needs to support this, x86 for
231 example does by saving things in the RTC, see below.
232
233 The architecture specific code must provide the extern
234 functions from <linux/resume-trace.h> as well as the
235 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
236
237 The way the information is presented is architecture-
238 dependent, x86 will print the information during a
239 late_initcall.
240
241config PM_TRACE_RTC
242 bool "Suspend/resume event tracing"
243 depends on PM_SLEEP_DEBUG
244 depends on X86
245 select PM_TRACE
246 help
247 This enables some cheesy code to save the last PM event point in the
248 RTC across reboots, so that you can debug a machine that just hangs
249 during suspend (or more commonly, during resume).
250
251 To use this debugging feature you should attempt to suspend the
252 machine, reboot it and then run
253
254 dmesg -s 1000000 | grep 'hash matches'
255
256 CAUTION: this option will cause your machine's real-time clock to be
257 set to an invalid time after a resume.
258
259config APM_EMULATION
260 tristate "Advanced Power Management Emulation"
261 depends on SYS_SUPPORTS_APM_EMULATION
262 help
263 APM is a BIOS specification for saving power using several different
264 techniques. This is mostly useful for battery powered laptops with
265 APM compliant BIOSes. If you say Y here, the system time will be
266 reset after a RESUME operation, the /proc/apm device will provide
267 battery status information, and user-space programs will receive
268 notification of APM "events" (e.g. battery status change).
269
270 In order to use APM, you will need supporting software. For location
271 and more information, read <file:Documentation/power/apm-acpi.rst>
272 and the Battery Powered Linux mini-HOWTO, available from
273 <http://www.tldp.org/docs.html#howto>.
274
275 This driver does not spin down disk drives (see the hdparm(8)
276 manpage ("man 8 hdparm") for that), and it doesn't turn off
277 VESA-compliant "green" monitors.
278
279 Generally, if you don't have a battery in your machine, there isn't
280 much point in using this driver and you should say N. If you get
281 random kernel OOPSes or reboots that don't seem to be related to
282 anything, try disabling/enabling this option (or disabling/enabling
283 APM in your BIOS).
284
285config PM_CLK
286 def_bool y
287 depends on PM && HAVE_CLK
288
289config PM_GENERIC_DOMAINS
290 bool
291 depends on PM
292
293config WQ_POWER_EFFICIENT_DEFAULT
294 bool "Enable workqueue power-efficient mode by default"
295 depends on PM
296 default n
297 help
298 Per-cpu workqueues are generally preferred because they show
299 better performance thanks to cache locality; unfortunately,
300 per-cpu workqueues tend to be more power hungry than unbound
301 workqueues.
302
303 Enabling workqueue.power_efficient kernel parameter makes the
304 per-cpu workqueues which were observed to contribute
305 significantly to power consumption unbound, leading to measurably
306 lower power usage at the cost of small performance overhead.
307
308 This config option determines whether workqueue.power_efficient
309 is enabled by default.
310
311 If in doubt, say N.
312
313config PM_GENERIC_DOMAINS_SLEEP
314 def_bool y
315 depends on PM_SLEEP && PM_GENERIC_DOMAINS
316
317config PM_GENERIC_DOMAINS_OF
318 def_bool y
319 depends on PM_GENERIC_DOMAINS && OF
320
321config CPU_PM
322 bool
323
324config ENERGY_MODEL
325 bool "Energy Model for CPUs"
326 depends on SMP
327 depends on CPU_FREQ
328 default n
329 help
330 Several subsystems (thermal and/or the task scheduler for example)
331 can leverage information about the energy consumed by CPUs to make
332 smarter decisions. This config option enables the framework from
333 which subsystems can access the energy models.
334
335 The exact usage of the energy model is subsystem-dependent.
336
337 If in doubt, say N.
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
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 60
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_OPP
263 bool
264 select SRCU
265 ---help---
266 SOCs have a standard set of tuples consisting of frequency and
267 voltage pairs that the device will support per voltage domain. This
268 is called Operating Performance Point or OPP. The actual definitions
269 of OPP varies over silicon within the same family of devices.
270
271 OPP layer organizes the data internally using device pointers
272 representing individual voltage domains and provides SOC
273 implementations a ready to use framework to manage OPPs.
274 For more information, read <file:Documentation/power/opp.txt>
275
276config PM_CLK
277 def_bool y
278 depends on PM && HAVE_CLK
279
280config PM_GENERIC_DOMAINS
281 bool
282 depends on PM
283
284config WQ_POWER_EFFICIENT_DEFAULT
285 bool "Enable workqueue power-efficient mode by default"
286 depends on PM
287 default n
288 help
289 Per-cpu workqueues are generally preferred because they show
290 better performance thanks to cache locality; unfortunately,
291 per-cpu workqueues tend to be more power hungry than unbound
292 workqueues.
293
294 Enabling workqueue.power_efficient kernel parameter makes the
295 per-cpu workqueues which were observed to contribute
296 significantly to power consumption unbound, leading to measurably
297 lower power usage at the cost of small performance overhead.
298
299 This config option determines whether workqueue.power_efficient
300 is enabled by default.
301
302 If in doubt, say N.
303
304config PM_GENERIC_DOMAINS_SLEEP
305 def_bool y
306 depends on PM_SLEEP && PM_GENERIC_DOMAINS
307
308config PM_GENERIC_DOMAINS_OF
309 def_bool y
310 depends on PM_GENERIC_DOMAINS && OF
311
312config CPU_PM
313 bool