2 bool "Suspend to RAM and standby"
3 depends on ARCH_SUSPEND_POSSIBLE
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).
10 config SUSPEND_FREEZER
11 bool "Enable freezer for suspend to RAM/standby" \
12 if ARCH_WANTS_FREEZER_CONTROL || BROKEN
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.
19 Turning OFF this setting is NOT recommended! If in doubt, say Y.
29 config HIBERNATE_CALLBACKS
33 bool "Hibernation (aka 'suspend to disk')"
34 depends on SWAP && ARCH_HIBERNATION_POSSIBLE
35 select HIBERNATE_CALLBACKS
40 Enable the suspend to disk (STD) functionality, which is usually
41 called "hibernation" in user interfaces. STD checkpoints the
42 system and powers it off; and restores that checkpoint on reboot.
44 You can suspend your machine with 'echo disk > /sys/power/state'
45 after placing resume=/dev/swappartition on the kernel command line
46 in your bootloader's configuration file.
48 Alternatively, you can use the additional userland tools available
49 from <http://suspend.sf.net>.
51 In principle it does not require ACPI or APM, although for example
52 ACPI will be used for the final steps when it is available. One
53 of the reasons to use software suspend is that the firmware hooks
54 for suspend states like suspend-to-RAM (STR) often don't work very
57 It creates an image which is saved in your active swap. Upon the next
58 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
59 have it detect the saved image, restore memory state from it, and
60 continue to run as before. If you do not want the previous state to
61 be reloaded, then use the 'noresume' kernel command line argument.
62 Note, however, that fsck will be run on your filesystems and you will
63 need to run mkswap against the swap partition used for the suspend.
65 It also works with swap files to a limited extent (for details see
66 <file:Documentation/power/swsusp-and-swap-files.txt>).
68 Right now you may boot without resuming and resume later but in the
69 meantime you cannot use the swap partition(s)/file(s) involved in
70 suspending. Also in this case you must not use the filesystems
71 that were mounted before the suspend. In particular, you MUST NOT
72 MOUNT any journaled filesystems mounted before the suspend or they
73 will get corrupted in a nasty way.
75 For more information take a look at <file:Documentation/power/swsusp.txt>.
77 config ARCH_SAVE_PAGE_KEYS
80 config PM_STD_PARTITION
81 string "Default resume partition"
82 depends on HIBERNATION
85 The default resume partition is the partition that the suspend-
86 to-disk implementation will look for a suspended disk image.
88 The partition specified here will be different for almost every user.
89 It should be a valid swap partition (at least for now) that is turned
92 The partition specified can be overridden by specifying:
94 resume=/dev/<other device>
96 which will set the resume partition to the device specified.
98 Note there is currently not a way to specify which device to save the
99 suspended image to. It will simply pick the first available swap
104 depends on SUSPEND || HIBERNATE_CALLBACKS
109 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
115 bool "Opportunistic sleep"
119 Allow the kernel to trigger a system transition into a global sleep
120 state automatically whenever there are no active wakeup sources.
123 bool "User space wakeup sources interface"
127 Allow user space to create, activate and deactivate wakeup source
128 objects with the help of a sysfs-based interface.
130 config PM_WAKELOCKS_LIMIT
131 int "Maximum number of user space wakeup sources (0 = no limit)"
134 depends on PM_WAKELOCKS
136 config PM_WAKELOCKS_GC
137 bool "Garbage collector for user space wakeup sources"
138 depends on PM_WAKELOCKS
142 bool "Run-time PM core functionality"
143 depends on !IA64_HP_SIM
145 Enable functionality allowing I/O devices to be put into energy-saving
146 (low power) states at run time (or autosuspended) after a specified
147 period of inactivity and woken up in response to a hardware-generated
148 wake-up event or a driver's request.
150 Hardware support is generally required for this functionality to work
151 and the bus type drivers of the buses the devices are on are
152 responsible for the actual handling of the autosuspend requests and
157 depends on PM_SLEEP || PM_RUNTIME
160 bool "Power Management Debug Support"
163 This option enables various debugging support in the Power Management
164 code. This is helpful when debugging and reporting PM bugs, like
167 config PM_ADVANCED_DEBUG
168 bool "Extra PM attributes in sysfs for low-level debugging/testing"
171 Add extra sysfs attributes allowing one to access some Power Management
172 fields of device objects from user space. If you are not a kernel
173 developer interested in debugging/testing Power Management, say "no".
175 config PM_TEST_SUSPEND
176 bool "Test suspend/resume and wakealarm during bootup"
177 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
179 This option will let you suspend your machine during bootup, and
180 make it wake up a few seconds later using an RTC wakeup alarm.
181 Enable this with a kernel parameter like "test_suspend=mem".
183 You probably want to have your system's RTC driver statically
184 linked, ensuring that it's available when this test runs.
186 config PM_SLEEP_DEBUG
188 depends on PM_DEBUG && PM_SLEEP
193 This enables code to save the last PM event point across
194 reboot. The architecture needs to support this, x86 for
195 example does by saving things in the RTC, see below.
197 The architecture specific code must provide the extern
198 functions from <linux/resume-trace.h> as well as the
199 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
201 The way the information is presented is architecture-
202 dependent, x86 will print the information during a
206 bool "Suspend/resume event tracing"
207 depends on PM_SLEEP_DEBUG
211 This enables some cheesy code to save the last PM event point in the
212 RTC across reboots, so that you can debug a machine that just hangs
213 during suspend (or more commonly, during resume).
215 To use this debugging feature you should attempt to suspend the
216 machine, reboot it and then run
218 dmesg -s 1000000 | grep 'hash matches'
220 CAUTION: this option will cause your machine's real-time clock to be
221 set to an invalid time after a resume.
224 tristate "Advanced Power Management Emulation"
225 depends on PM && SYS_SUPPORTS_APM_EMULATION
227 APM is a BIOS specification for saving power using several different
228 techniques. This is mostly useful for battery powered laptops with
229 APM compliant BIOSes. If you say Y here, the system time will be
230 reset after a RESUME operation, the /proc/apm device will provide
231 battery status information, and user-space programs will receive
232 notification of APM "events" (e.g. battery status change).
234 In order to use APM, you will need supporting software. For location
235 and more information, read <file:Documentation/power/apm-acpi.txt>
236 and the Battery Powered Linux mini-HOWTO, available from
237 <http://www.tldp.org/docs.html#howto>.
239 This driver does not spin down disk drives (see the hdparm(8)
240 manpage ("man 8 hdparm") for that), and it doesn't turn off
241 VESA-compliant "green" monitors.
243 Generally, if you don't have a battery in your machine, there isn't
244 much point in using this driver and you should say N. If you get
245 random kernel OOPSes or reboots that don't seem to be related to
246 anything, try disabling/enabling this option (or disabling/enabling
253 bool "Operating Performance Point (OPP) Layer library"
254 depends on ARCH_HAS_OPP
256 SOCs have a standard set of tuples consisting of frequency and
257 voltage pairs that the device will support per voltage domain. This
258 is called Operating Performance Point or OPP. The actual definitions
259 of OPP varies over silicon within the same family of devices.
261 OPP layer organizes the data internally using device pointers
262 representing individual voltage domains and provides SOC
263 implementations a ready to use framework to manage OPPs.
264 For more information, read <file:Documentation/power/opp.txt>
268 depends on PM && HAVE_CLK
270 config PM_GENERIC_DOMAINS
274 config WQ_POWER_EFFICIENT_DEFAULT
275 bool "Enable workqueue power-efficient mode by default"
279 Per-cpu workqueues are generally preferred because they show
280 better performance thanks to cache locality; unfortunately,
281 per-cpu workqueues tend to be more power hungry than unbound
284 Enabling workqueue.power_efficient kernel parameter makes the
285 per-cpu workqueues which were observed to contribute
286 significantly to power consumption unbound, leading to measurably
287 lower power usage at the cost of small performance overhead.
289 This config option determines whether workqueue.power_efficient
290 is enabled by default.
294 config PM_GENERIC_DOMAINS_SLEEP
296 depends on PM_SLEEP && PM_GENERIC_DOMAINS
298 config PM_GENERIC_DOMAINS_RUNTIME
300 depends on PM_RUNTIME && PM_GENERIC_DOMAINS
302 config PM_GENERIC_DOMAINS_OF
304 depends on PM_GENERIC_DOMAINS && OF && !ARCH_EXYNOS
308 depends on SUSPEND || CPU_IDLE
311 bool "Log time spent in suspend"
313 Prints the time spent in suspend in the kernel log, and
314 keeps statistics on the time spent in suspend in
315 /sys/kernel/debug/suspend_time