xref: /linux/kernel/power/Kconfig (revision a1ce39288e6fbefdd8d607021d02384eb4a20b99)
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
104	select HOTPLUG_CPU
105
106config PM_AUTOSLEEP
107	bool "Opportunistic sleep"
108	depends on PM_SLEEP
109	default n
110	---help---
111	Allow the kernel to trigger a system transition into a global sleep
112	state automatically whenever there are no active wakeup sources.
113
114config PM_WAKELOCKS
115	bool "User space wakeup sources interface"
116	depends on PM_SLEEP
117	default n
118	---help---
119	Allow user space to create, activate and deactivate wakeup source
120	objects with the help of a sysfs-based interface.
121
122config PM_WAKELOCKS_LIMIT
123	int "Maximum number of user space wakeup sources (0 = no limit)"
124	range 0 100000
125	default 100
126	depends on PM_WAKELOCKS
127
128config PM_WAKELOCKS_GC
129	bool "Garbage collector for user space wakeup sources"
130	depends on PM_WAKELOCKS
131	default y
132
133config PM_RUNTIME
134	bool "Run-time PM core functionality"
135	depends on !IA64_HP_SIM
136	---help---
137	  Enable functionality allowing I/O devices to be put into energy-saving
138	  (low power) states at run time (or autosuspended) after a specified
139	  period of inactivity and woken up in response to a hardware-generated
140	  wake-up event or a driver's request.
141
142	  Hardware support is generally required for this functionality to work
143	  and the bus type drivers of the buses the devices are on are
144	  responsible for the actual handling of the autosuspend requests and
145	  wake-up events.
146
147config PM
148	def_bool y
149	depends on PM_SLEEP || PM_RUNTIME
150
151config PM_DEBUG
152	bool "Power Management Debug Support"
153	depends on PM
154	---help---
155	This option enables various debugging support in the Power Management
156	code. This is helpful when debugging and reporting PM bugs, like
157	suspend support.
158
159config PM_ADVANCED_DEBUG
160	bool "Extra PM attributes in sysfs for low-level debugging/testing"
161	depends on PM_DEBUG
162	---help---
163	Add extra sysfs attributes allowing one to access some Power Management
164	fields of device objects from user space.  If you are not a kernel
165	developer interested in debugging/testing Power Management, say "no".
166
167config PM_TEST_SUSPEND
168	bool "Test suspend/resume and wakealarm during bootup"
169	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
170	---help---
171	This option will let you suspend your machine during bootup, and
172	make it wake up a few seconds later using an RTC wakeup alarm.
173	Enable this with a kernel parameter like "test_suspend=mem".
174
175	You probably want to have your system's RTC driver statically
176	linked, ensuring that it's available when this test runs.
177
178config PM_SLEEP_DEBUG
179	def_bool y
180	depends on PM_DEBUG && PM_SLEEP
181
182config PM_TRACE
183	bool
184	help
185	  This enables code to save the last PM event point across
186	  reboot. The architecture needs to support this, x86 for
187	  example does by saving things in the RTC, see below.
188
189	  The architecture specific code must provide the extern
190	  functions from <linux/resume-trace.h> as well as the
191	  <asm/resume-trace.h> header with a TRACE_RESUME() macro.
192
193	  The way the information is presented is architecture-
194	  dependent, x86 will print the information during a
195	  late_initcall.
196
197config PM_TRACE_RTC
198	bool "Suspend/resume event tracing"
199	depends on PM_SLEEP_DEBUG
200	depends on X86
201	select PM_TRACE
202	---help---
203	This enables some cheesy code to save the last PM event point in the
204	RTC across reboots, so that you can debug a machine that just hangs
205	during suspend (or more commonly, during resume).
206
207	To use this debugging feature you should attempt to suspend the
208	machine, reboot it and then run
209
210		dmesg -s 1000000 | grep 'hash matches'
211
212	CAUTION: this option will cause your machine's real-time clock to be
213	set to an invalid time after a resume.
214
215config APM_EMULATION
216	tristate "Advanced Power Management Emulation"
217	depends on PM && SYS_SUPPORTS_APM_EMULATION
218	help
219	  APM is a BIOS specification for saving power using several different
220	  techniques. This is mostly useful for battery powered laptops with
221	  APM compliant BIOSes. If you say Y here, the system time will be
222	  reset after a RESUME operation, the /proc/apm device will provide
223	  battery status information, and user-space programs will receive
224	  notification of APM "events" (e.g. battery status change).
225
226	  In order to use APM, you will need supporting software. For location
227	  and more information, read <file:Documentation/power/apm-acpi.txt>
228	  and the Battery Powered Linux mini-HOWTO, available from
229	  <http://www.tldp.org/docs.html#howto>.
230
231	  This driver does not spin down disk drives (see the hdparm(8)
232	  manpage ("man 8 hdparm") for that), and it doesn't turn off
233	  VESA-compliant "green" monitors.
234
235	  Generally, if you don't have a battery in your machine, there isn't
236	  much point in using this driver and you should say N. If you get
237	  random kernel OOPSes or reboots that don't seem to be related to
238	  anything, try disabling/enabling this option (or disabling/enabling
239	  APM in your BIOS).
240
241config ARCH_HAS_OPP
242	bool
243
244config PM_OPP
245	bool "Operating Performance Point (OPP) Layer library"
246	depends on ARCH_HAS_OPP
247	---help---
248	  SOCs have a standard set of tuples consisting of frequency and
249	  voltage pairs that the device will support per voltage domain. This
250	  is called Operating Performance Point or OPP. The actual definitions
251	  of OPP varies over silicon within the same family of devices.
252
253	  OPP layer organizes the data internally using device pointers
254	  representing individual voltage domains and provides SOC
255	  implementations a ready to use framework to manage OPPs.
256	  For more information, read <file:Documentation/power/opp.txt>
257
258config PM_CLK
259	def_bool y
260	depends on PM && HAVE_CLK
261
262config PM_GENERIC_DOMAINS
263	bool
264	depends on PM
265
266config PM_GENERIC_DOMAINS_RUNTIME
267	def_bool y
268	depends on PM_RUNTIME && PM_GENERIC_DOMAINS
269
270config CPU_PM
271	bool
272	depends on SUSPEND || CPU_IDLE
273