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	select CRC32
 31	---help---
 32	  Enable the suspend to disk (STD) functionality, which is usually
 33	  called "hibernation" in user interfaces.  STD checkpoints the
 34	  system and powers it off; and restores that checkpoint on reboot.
 35
 36	  You can suspend your machine with 'echo disk > /sys/power/state'
 37	  after placing resume=/dev/swappartition on the kernel command line
 38	  in your bootloader's configuration file.
 39
 40	  Alternatively, you can use the additional userland tools available
 41	  from <http://suspend.sf.net>.
 42
 43	  In principle it does not require ACPI or APM, although for example
 44	  ACPI will be used for the final steps when it is available.  One
 45	  of the reasons to use software suspend is that the firmware hooks
 46	  for suspend states like suspend-to-RAM (STR) often don't work very
 47	  well with Linux.
 48
 49	  It creates an image which is saved in your active swap. Upon the next
 50	  boot, pass the 'resume=/dev/swappartition' argument to the kernel to
 51	  have it detect the saved image, restore memory state from it, and
 52	  continue to run as before. If you do not want the previous state to
 53	  be reloaded, then use the 'noresume' kernel command line argument.
 54	  Note, however, that fsck will be run on your filesystems and you will
 55	  need to run mkswap against the swap partition used for the suspend.
 56
 57	  It also works with swap files to a limited extent (for details see
 58	  <file:Documentation/power/swsusp-and-swap-files.txt>).
 59
 60	  Right now you may boot without resuming and resume later but in the
 61	  meantime you cannot use the swap partition(s)/file(s) involved in
 62	  suspending.  Also in this case you must not use the filesystems
 63	  that were mounted before the suspend.  In particular, you MUST NOT
 64	  MOUNT any journaled filesystems mounted before the suspend or they
 65	  will get corrupted in a nasty way.
 66
 67	  For more information take a look at <file:Documentation/power/swsusp.txt>.
 68
 69config ARCH_SAVE_PAGE_KEYS
 70	bool
 
 
 
 
 
 
 
 
 
 71
 72config PM_STD_PARTITION
 73	string "Default resume partition"
 74	depends on HIBERNATION
 75	default ""
 76	---help---
 77	  The default resume partition is the partition that the suspend-
 78	  to-disk implementation will look for a suspended disk image. 
 79
 80	  The partition specified here will be different for almost every user. 
 81	  It should be a valid swap partition (at least for now) that is turned
 82	  on before suspending. 
 83
 84	  The partition specified can be overridden by specifying:
 85
 86		resume=/dev/<other device> 
 87
 88	  which will set the resume partition to the device specified. 
 89
 90	  Note there is currently not a way to specify which device to save the
 91	  suspended image to. It will simply pick the first available swap 
 92	  device.
 93
 94config PM_SLEEP
 95	def_bool y
 96	depends on SUSPEND || HIBERNATE_CALLBACKS
 
 97
 98config PM_SLEEP_SMP
 99	def_bool y
100	depends on SMP
101	depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
102	depends on PM_SLEEP
103	select HOTPLUG_CPU
104
 
 
 
 
 
 
 
 
 
105config PM_AUTOSLEEP
106	bool "Opportunistic sleep"
107	depends on PM_SLEEP
108	default n
109	---help---
110	Allow the kernel to trigger a system transition into a global sleep
111	state automatically whenever there are no active wakeup sources.
112
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
113config PM_WAKELOCKS
114	bool "User space wakeup sources interface"
115	depends on PM_SLEEP
116	default n
117	---help---
118	Allow user space to create, activate and deactivate wakeup source
119	objects with the help of a sysfs-based interface.
120
121config PM_WAKELOCKS_LIMIT
122	int "Maximum number of user space wakeup sources (0 = no limit)"
123	range 0 100000
124	default 100
125	depends on PM_WAKELOCKS
126
127config PM_WAKELOCKS_GC
128	bool "Garbage collector for user space wakeup sources"
129	depends on PM_WAKELOCKS
130	default y
131
132config PM_RUNTIME
133	bool "Run-time PM core functionality"
134	depends on !IA64_HP_SIM
135	---help---
136	  Enable functionality allowing I/O devices to be put into energy-saving
137	  (low power) states at run time (or autosuspended) after a specified
138	  period of inactivity and woken up in response to a hardware-generated
139	  wake-up event or a driver's request.
140
141	  Hardware support is generally required for this functionality to work
142	  and the bus type drivers of the buses the devices are on are
143	  responsible for the actual handling of the autosuspend requests and
144	  wake-up events.
145
146config PM
147	def_bool y
148	depends on PM_SLEEP || PM_RUNTIME
149
150config PM_DEBUG
151	bool "Power Management Debug Support"
152	depends on PM
153	---help---
154	This option enables various debugging support in the Power Management
155	code. This is helpful when debugging and reporting PM bugs, like
156	suspend support.
157
158config PM_ADVANCED_DEBUG
159	bool "Extra PM attributes in sysfs for low-level debugging/testing"
160	depends on PM_DEBUG
161	---help---
162	Add extra sysfs attributes allowing one to access some Power Management
163	fields of device objects from user space.  If you are not a kernel
164	developer interested in debugging/testing Power Management, say "no".
165
166config PM_TEST_SUSPEND
167	bool "Test suspend/resume and wakealarm during bootup"
168	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
169	---help---
170	This option will let you suspend your machine during bootup, and
171	make it wake up a few seconds later using an RTC wakeup alarm.
172	Enable this with a kernel parameter like "test_suspend=mem".
173
174	You probably want to have your system's RTC driver statically
175	linked, ensuring that it's available when this test runs.
176
177config PM_SLEEP_DEBUG
178	def_bool y
179	depends on PM_DEBUG && PM_SLEEP
180
181config DPM_WATCHDOG
182	bool "Device suspend/resume watchdog"
183	depends on PM_DEBUG && PSTORE
184	---help---
185	  Sets up a watchdog timer to capture drivers that are
186	  locked up attempting to suspend/resume a device.
187	  A detected lockup causes system panic with message
188	  captured in pstore device for inspection in subsequent
189	  boot session.
190
191config DPM_WATCHDOG_TIMEOUT
192	int "Watchdog timeout in seconds"
193	range 1 120
194	default 12
195	depends on DPM_WATCHDOG
196
197config PM_TRACE
198	bool
199	help
200	  This enables code to save the last PM event point across
201	  reboot. The architecture needs to support this, x86 for
202	  example does by saving things in the RTC, see below.
203
204	  The architecture specific code must provide the extern
205	  functions from <linux/resume-trace.h> as well as the
206	  <asm/resume-trace.h> header with a TRACE_RESUME() macro.
207
208	  The way the information is presented is architecture-
209	  dependent, x86 will print the information during a
210	  late_initcall.
211
212config PM_TRACE_RTC
213	bool "Suspend/resume event tracing"
214	depends on PM_SLEEP_DEBUG
215	depends on X86
216	select PM_TRACE
217	---help---
218	This enables some cheesy code to save the last PM event point in the
219	RTC across reboots, so that you can debug a machine that just hangs
220	during suspend (or more commonly, during resume).
221
222	To use this debugging feature you should attempt to suspend the
223	machine, reboot it and then run
224
225		dmesg -s 1000000 | grep 'hash matches'
226
227	CAUTION: this option will cause your machine's real-time clock to be
228	set to an invalid time after a resume.
229
230config APM_EMULATION
231	tristate "Advanced Power Management Emulation"
232	depends on PM && SYS_SUPPORTS_APM_EMULATION
233	help
234	  APM is a BIOS specification for saving power using several different
235	  techniques. This is mostly useful for battery powered laptops with
236	  APM compliant BIOSes. If you say Y here, the system time will be
237	  reset after a RESUME operation, the /proc/apm device will provide
238	  battery status information, and user-space programs will receive
239	  notification of APM "events" (e.g. battery status change).
240
241	  In order to use APM, you will need supporting software. For location
242	  and more information, read <file:Documentation/power/apm-acpi.txt>
243	  and the Battery Powered Linux mini-HOWTO, available from
244	  <http://www.tldp.org/docs.html#howto>.
245
246	  This driver does not spin down disk drives (see the hdparm(8)
247	  manpage ("man 8 hdparm") for that), and it doesn't turn off
248	  VESA-compliant "green" monitors.
249
250	  Generally, if you don't have a battery in your machine, there isn't
251	  much point in using this driver and you should say N. If you get
252	  random kernel OOPSes or reboots that don't seem to be related to
253	  anything, try disabling/enabling this option (or disabling/enabling
254	  APM in your BIOS).
255
256config ARCH_HAS_OPP
257	bool
258
259config PM_OPP
260	bool "Operating Performance Point (OPP) Layer library"
261	depends on ARCH_HAS_OPP
262	---help---
263	  SOCs have a standard set of tuples consisting of frequency and
264	  voltage pairs that the device will support per voltage domain. This
265	  is called Operating Performance Point or OPP. The actual definitions
266	  of OPP varies over silicon within the same family of devices.
267
268	  OPP layer organizes the data internally using device pointers
269	  representing individual voltage domains and provides SOC
270	  implementations a ready to use framework to manage OPPs.
271	  For more information, read <file:Documentation/power/opp.txt>
272
273config PM_CLK
274	def_bool y
275	depends on PM && HAVE_CLK
276
277config PM_GENERIC_DOMAINS
278	bool
279	depends on PM
280
281config WQ_POWER_EFFICIENT_DEFAULT
282	bool "Enable workqueue power-efficient mode by default"
283	depends on PM
284	default n
285	help
286	  Per-cpu workqueues are generally preferred because they show
287	  better performance thanks to cache locality; unfortunately,
288	  per-cpu workqueues tend to be more power hungry than unbound
289	  workqueues.
290
291	  Enabling workqueue.power_efficient kernel parameter makes the
292	  per-cpu workqueues which were observed to contribute
293	  significantly to power consumption unbound, leading to measurably
294	  lower power usage at the cost of small performance overhead.
295
296	  This config option determines whether workqueue.power_efficient
297	  is enabled by default.
298
299	  If in doubt, say N.
300
301config PM_GENERIC_DOMAINS_SLEEP
302	def_bool y
303	depends on PM_SLEEP && PM_GENERIC_DOMAINS
304
305config PM_GENERIC_DOMAINS_RUNTIME
306	def_bool y
307	depends on PM_RUNTIME && PM_GENERIC_DOMAINS
308
309config CPU_PM
310	bool
311	depends on SUSPEND || CPU_IDLE
 
 
 
 
 
 
 
 
 
 
 
 
 

  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.