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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.
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 help
143 Allow the kernel to trigger a system transition into a global sleep
144 state automatically whenever there are no active wakeup sources.
145
146config PM_USERSPACE_AUTOSLEEP
147 bool "Userspace opportunistic sleep"
148 depends on PM_SLEEP
149 help
150 Notify kernel of aggressive userspace autosleep power management policy.
151
152 This option changes the behavior of various sleep-sensitive code to deal
153 with frequent userspace-initiated transitions into a global sleep state.
154
155 Saying Y here, disables code paths that most users really should keep
156 enabled. In particular, only enable this if it is very common to be
157 asleep/awake for very short periods of time (<= 2 seconds).
158
159 Only platforms, such as Android, that implement opportunistic sleep from
160 a userspace power manager service should enable this option; and not
161 other machines. Therefore, you should say N here, unless you are
162 extremely certain that this is what you want. The option otherwise has
163 bad, undesirable effects, and should not be enabled just for fun.
164
165
166config PM_WAKELOCKS
167 bool "User space wakeup sources interface"
168 depends on PM_SLEEP
169 help
170 Allow user space to create, activate and deactivate wakeup source
171 objects with the help of a sysfs-based interface.
172
173config PM_WAKELOCKS_LIMIT
174 int "Maximum number of user space wakeup sources (0 = no limit)"
175 range 0 100000
176 default 100
177 depends on PM_WAKELOCKS
178
179config PM_WAKELOCKS_GC
180 bool "Garbage collector for user space wakeup sources"
181 depends on PM_WAKELOCKS
182 default y
183
184config PM
185 bool "Device power management core functionality"
186 help
187 Enable functionality allowing I/O devices to be put into energy-saving
188 (low power) states, for example after a specified period of inactivity
189 (autosuspended), and woken up in response to a hardware-generated
190 wake-up event or a driver's request.
191
192 Hardware support is generally required for this functionality to work
193 and the bus type drivers of the buses the devices are on are
194 responsible for the actual handling of device suspend requests and
195 wake-up events.
196
197config PM_DEBUG
198 bool "Power Management Debug Support"
199 depends on PM
200 help
201 This option enables various debugging support in the Power Management
202 code. This is helpful when debugging and reporting PM bugs, like
203 suspend support.
204
205config PM_ADVANCED_DEBUG
206 bool "Extra PM attributes in sysfs for low-level debugging/testing"
207 depends on PM_DEBUG
208 help
209 Add extra sysfs attributes allowing one to access some Power Management
210 fields of device objects from user space. If you are not a kernel
211 developer interested in debugging/testing Power Management, say "no".
212
213config PM_TEST_SUSPEND
214 bool "Test suspend/resume and wakealarm during bootup"
215 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
216 help
217 This option will let you suspend your machine during bootup, and
218 make it wake up a few seconds later using an RTC wakeup alarm.
219 Enable this with a kernel parameter like "test_suspend=mem".
220
221 You probably want to have your system's RTC driver statically
222 linked, ensuring that it's available when this test runs.
223
224config PM_SLEEP_DEBUG
225 def_bool y
226 depends on PM_DEBUG && PM_SLEEP
227
228config DPM_WATCHDOG
229 bool "Device suspend/resume watchdog"
230 depends on PM_DEBUG && PSTORE && EXPERT
231 help
232 Sets up a watchdog timer to capture drivers that are
233 locked up attempting to suspend/resume a device.
234 A detected lockup causes system panic with message
235 captured in pstore device for inspection in subsequent
236 boot session.
237
238config DPM_WATCHDOG_TIMEOUT
239 int "Watchdog timeout in seconds"
240 range 1 120
241 default 120
242 depends on DPM_WATCHDOG
243
244config PM_TRACE
245 bool
246 help
247 This enables code to save the last PM event point across
248 reboot. The architecture needs to support this, x86 for
249 example does by saving things in the RTC, see below.
250
251 The architecture specific code must provide the extern
252 functions from <linux/resume-trace.h> as well as the
253 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
254
255 The way the information is presented is architecture-
256 dependent, x86 will print the information during a
257 late_initcall.
258
259config PM_TRACE_RTC
260 bool "Suspend/resume event tracing"
261 depends on PM_SLEEP_DEBUG
262 depends on X86
263 select PM_TRACE
264 help
265 This enables some cheesy code to save the last PM event point in the
266 RTC across reboots, so that you can debug a machine that just hangs
267 during suspend (or more commonly, during resume).
268
269 To use this debugging feature you should attempt to suspend the
270 machine, reboot it and then run
271
272 dmesg -s 1000000 | grep 'hash matches'
273
274 CAUTION: this option will cause your machine's real-time clock to be
275 set to an invalid time after a resume.
276
277config APM_EMULATION
278 tristate "Advanced Power Management Emulation"
279 depends on SYS_SUPPORTS_APM_EMULATION
280 help
281 APM is a BIOS specification for saving power using several different
282 techniques. This is mostly useful for battery powered laptops with
283 APM compliant BIOSes. If you say Y here, the system time will be
284 reset after a RESUME operation, the /proc/apm device will provide
285 battery status information, and user-space programs will receive
286 notification of APM "events" (e.g. battery status change).
287
288 In order to use APM, you will need supporting software. For location
289 and more information, read <file:Documentation/power/apm-acpi.rst>
290 and the Battery Powered Linux mini-HOWTO, available from
291 <http://www.tldp.org/docs.html#howto>.
292
293 This driver does not spin down disk drives (see the hdparm(8)
294 manpage ("man 8 hdparm") for that), and it doesn't turn off
295 VESA-compliant "green" monitors.
296
297 Generally, if you don't have a battery in your machine, there isn't
298 much point in using this driver and you should say N. If you get
299 random kernel OOPSes or reboots that don't seem to be related to
300 anything, try disabling/enabling this option (or disabling/enabling
301 APM in your BIOS).
302
303config PM_CLK
304 def_bool y
305 depends on PM && HAVE_CLK
306
307config PM_GENERIC_DOMAINS
308 bool
309 depends on PM
310
311config WQ_POWER_EFFICIENT_DEFAULT
312 bool "Enable workqueue power-efficient mode by default"
313 depends on PM
314 help
315 Per-cpu workqueues are generally preferred because they show
316 better performance thanks to cache locality; unfortunately,
317 per-cpu workqueues tend to be more power hungry than unbound
318 workqueues.
319
320 Enabling workqueue.power_efficient kernel parameter makes the
321 per-cpu workqueues which were observed to contribute
322 significantly to power consumption unbound, leading to measurably
323 lower power usage at the cost of small performance overhead.
324
325 This config option determines whether workqueue.power_efficient
326 is enabled by default.
327
328 If in doubt, say N.
329
330config PM_GENERIC_DOMAINS_SLEEP
331 def_bool y
332 depends on PM_SLEEP && PM_GENERIC_DOMAINS
333
334config PM_GENERIC_DOMAINS_OF
335 def_bool y
336 depends on PM_GENERIC_DOMAINS && OF
337
338config CPU_PM
339 bool
340
341config ENERGY_MODEL
342 bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)"
343 depends on SMP
344 depends on CPU_FREQ
345 help
346 Several subsystems (thermal and/or the task scheduler for example)
347 can leverage information about the energy consumed by devices to
348 make smarter decisions. This config option enables the framework
349 from which subsystems can access the energy models.
350
351 The exact usage of the energy model is subsystem-dependent.
352
353 If in doubt, say N.