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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 HIBERNATE_CALLBACKS
22 bool
23
24config HIBERNATION
25 bool "Hibernation (aka 'suspend to disk')"
26 depends on SWAP && ARCH_HIBERNATION_POSSIBLE
27 select HIBERNATE_CALLBACKS
28 select LZO_COMPRESS
29 select LZO_DECOMPRESS
30 ---help---
31 Enable the suspend to disk (STD) functionality, which is usually
32 called "hibernation" in user interfaces. STD checkpoints the
33 system and powers it off; and restores that checkpoint on reboot.
34
35 You can suspend your machine with 'echo disk > /sys/power/state'
36 after placing resume=/dev/swappartition on the kernel command line
37 in your bootloader's configuration file.
38
39 Alternatively, you can use the additional userland tools available
40 from <http://suspend.sf.net>.
41
42 In principle it does not require ACPI or APM, although for example
43 ACPI will be used for the final steps when it is available. One
44 of the reasons to use software suspend is that the firmware hooks
45 for suspend states like suspend-to-RAM (STR) often don't work very
46 well with Linux.
47
48 It creates an image which is saved in your active swap. Upon the next
49 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
50 have it detect the saved image, restore memory state from it, and
51 continue to run as before. If you do not want the previous state to
52 be reloaded, then use the 'noresume' kernel command line argument.
53 Note, however, that fsck will be run on your filesystems and you will
54 need to run mkswap against the swap partition used for the suspend.
55
56 It also works with swap files to a limited extent (for details see
57 <file:Documentation/power/swsusp-and-swap-files.txt>).
58
59 Right now you may boot without resuming and resume later but in the
60 meantime you cannot use the swap partition(s)/file(s) involved in
61 suspending. Also in this case you must not use the filesystems
62 that were mounted before the suspend. In particular, you MUST NOT
63 MOUNT any journaled filesystems mounted before the suspend or they
64 will get corrupted in a nasty way.
65
66 For more information take a look at <file:Documentation/power/swsusp.txt>.
67
68config PM_STD_PARTITION
69 string "Default resume partition"
70 depends on HIBERNATION
71 default ""
72 ---help---
73 The default resume partition is the partition that the suspend-
74 to-disk implementation will look for a suspended disk image.
75
76 The partition specified here will be different for almost every user.
77 It should be a valid swap partition (at least for now) that is turned
78 on before suspending.
79
80 The partition specified can be overridden by specifying:
81
82 resume=/dev/<other device>
83
84 which will set the resume partition to the device specified.
85
86 Note there is currently not a way to specify which device to save the
87 suspended image to. It will simply pick the first available swap
88 device.
89
90config PM_SLEEP
91 def_bool y
92 depends on SUSPEND || HIBERNATE_CALLBACKS
93
94config PM_SLEEP_SMP
95 def_bool y
96 depends on SMP
97 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
98 depends on PM_SLEEP
99 select HOTPLUG
100 select HOTPLUG_CPU
101
102config PM_RUNTIME
103 bool "Run-time PM core functionality"
104 depends on !IA64_HP_SIM
105 ---help---
106 Enable functionality allowing I/O devices to be put into energy-saving
107 (low power) states at run time (or autosuspended) after a specified
108 period of inactivity and woken up in response to a hardware-generated
109 wake-up event or a driver's request.
110
111 Hardware support is generally required for this functionality to work
112 and the bus type drivers of the buses the devices are on are
113 responsible for the actual handling of the autosuspend requests and
114 wake-up events.
115
116config PM
117 def_bool y
118 depends on PM_SLEEP || PM_RUNTIME
119
120config PM_DEBUG
121 bool "Power Management Debug Support"
122 depends on PM
123 ---help---
124 This option enables various debugging support in the Power Management
125 code. This is helpful when debugging and reporting PM bugs, like
126 suspend support.
127
128config PM_ADVANCED_DEBUG
129 bool "Extra PM attributes in sysfs for low-level debugging/testing"
130 depends on PM_DEBUG
131 ---help---
132 Add extra sysfs attributes allowing one to access some Power Management
133 fields of device objects from user space. If you are not a kernel
134 developer interested in debugging/testing Power Management, say "no".
135
136config PM_TEST_SUSPEND
137 bool "Test suspend/resume and wakealarm during bootup"
138 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
139 ---help---
140 This option will let you suspend your machine during bootup, and
141 make it wake up a few seconds later using an RTC wakeup alarm.
142 Enable this with a kernel parameter like "test_suspend=mem".
143
144 You probably want to have your system's RTC driver statically
145 linked, ensuring that it's available when this test runs.
146
147config CAN_PM_TRACE
148 def_bool y
149 depends on PM_DEBUG && PM_SLEEP
150
151config PM_TRACE
152 bool
153 help
154 This enables code to save the last PM event point across
155 reboot. The architecture needs to support this, x86 for
156 example does by saving things in the RTC, see below.
157
158 The architecture specific code must provide the extern
159 functions from <linux/resume-trace.h> as well as the
160 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
161
162 The way the information is presented is architecture-
163 dependent, x86 will print the information during a
164 late_initcall.
165
166config PM_TRACE_RTC
167 bool "Suspend/resume event tracing"
168 depends on CAN_PM_TRACE
169 depends on X86
170 select PM_TRACE
171 ---help---
172 This enables some cheesy code to save the last PM event point in the
173 RTC across reboots, so that you can debug a machine that just hangs
174 during suspend (or more commonly, during resume).
175
176 To use this debugging feature you should attempt to suspend the
177 machine, reboot it and then run
178
179 dmesg -s 1000000 | grep 'hash matches'
180
181 CAUTION: this option will cause your machine's real-time clock to be
182 set to an invalid time after a resume.
183
184config APM_EMULATION
185 tristate "Advanced Power Management Emulation"
186 depends on PM && SYS_SUPPORTS_APM_EMULATION
187 help
188 APM is a BIOS specification for saving power using several different
189 techniques. This is mostly useful for battery powered laptops with
190 APM compliant BIOSes. If you say Y here, the system time will be
191 reset after a RESUME operation, the /proc/apm device will provide
192 battery status information, and user-space programs will receive
193 notification of APM "events" (e.g. battery status change).
194
195 In order to use APM, you will need supporting software. For location
196 and more information, read <file:Documentation/power/apm-acpi.txt>
197 and the Battery Powered Linux mini-HOWTO, available from
198 <http://www.tldp.org/docs.html#howto>.
199
200 This driver does not spin down disk drives (see the hdparm(8)
201 manpage ("man 8 hdparm") for that), and it doesn't turn off
202 VESA-compliant "green" monitors.
203
204 Generally, if you don't have a battery in your machine, there isn't
205 much point in using this driver and you should say N. If you get
206 random kernel OOPSes or reboots that don't seem to be related to
207 anything, try disabling/enabling this option (or disabling/enabling
208 APM in your BIOS).
209
210config ARCH_HAS_OPP
211 bool
212
213config PM_OPP
214 bool "Operating Performance Point (OPP) Layer library"
215 depends on ARCH_HAS_OPP
216 ---help---
217 SOCs have a standard set of tuples consisting of frequency and
218 voltage pairs that the device will support per voltage domain. This
219 is called Operating Performance Point or OPP. The actual definitions
220 of OPP varies over silicon within the same family of devices.
221
222 OPP layer organizes the data internally using device pointers
223 representing individual voltage domains and provides SOC
224 implementations a ready to use framework to manage OPPs.
225 For more information, read <file:Documentation/power/opp.txt>
226
227config PM_CLK
228 def_bool y
229 depends on PM && HAVE_CLK
230
231config PM_GENERIC_DOMAINS
232 bool
233 depends on PM
234
235config PM_GENERIC_DOMAINS_RUNTIME
236 def_bool y
237 depends on PM_RUNTIME && PM_GENERIC_DOMAINS
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.