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.
21 config SUSPEND_SKIP_SYNC
22 bool "Skip kernel's sys_sync() on suspend to RAM/standby"
26 Skip the kernel sys_sync() before freezing user processes.
27 Some systems prefer not to pay this cost on every invocation
28 of suspend, or they are content with invoking sync() from
29 user-space before invoking suspend. Say Y if that's your case.
36 bool "Android's method of preventing suspend"
39 This allows applications to prevent the CPU from suspending while
42 Say Y if you are running an android userspace.
44 config HIBERNATE_CALLBACKS
48 bool "Hibernation (aka 'suspend to disk')"
49 depends on SWAP && ARCH_HIBERNATION_POSSIBLE
50 select HIBERNATE_CALLBACKS
55 Enable the suspend to disk (STD) functionality, which is usually
56 called "hibernation" in user interfaces. STD checkpoints the
57 system and powers it off; and restores that checkpoint on reboot.
59 You can suspend your machine with 'echo disk > /sys/power/state'
60 after placing resume=/dev/swappartition on the kernel command line
61 in your bootloader's configuration file.
63 Alternatively, you can use the additional userland tools available
64 from <http://suspend.sf.net>.
66 In principle it does not require ACPI or APM, although for example
67 ACPI will be used for the final steps when it is available. One
68 of the reasons to use software suspend is that the firmware hooks
69 for suspend states like suspend-to-RAM (STR) often don't work very
72 It creates an image which is saved in your active swap. Upon the next
73 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
74 have it detect the saved image, restore memory state from it, and
75 continue to run as before. If you do not want the previous state to
76 be reloaded, then use the 'noresume' kernel command line argument.
77 Note, however, that fsck will be run on your filesystems and you will
78 need to run mkswap against the swap partition used for the suspend.
80 It also works with swap files to a limited extent (for details see
81 <file:Documentation/power/swsusp-and-swap-files.txt>).
83 Right now you may boot without resuming and resume later but in the
84 meantime you cannot use the swap partition(s)/file(s) involved in
85 suspending. Also in this case you must not use the filesystems
86 that were mounted before the suspend. In particular, you MUST NOT
87 MOUNT any journaled filesystems mounted before the suspend or they
88 will get corrupted in a nasty way.
90 For more information take a look at <file:Documentation/power/swsusp.txt>.
92 config ARCH_SAVE_PAGE_KEYS
95 config PM_STD_PARTITION
96 string "Default resume partition"
97 depends on HIBERNATION
100 The default resume partition is the partition that the suspend-
101 to-disk implementation will look for a suspended disk image.
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.
107 The partition specified can be overridden by specifying:
109 resume=/dev/<other device>
111 which will set the resume partition to the device specified.
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
119 depends on SUSPEND || HIBERNATE_CALLBACKS
125 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
130 bool "Opportunistic sleep"
134 Allow the kernel to trigger a system transition into a global sleep
135 state automatically whenever there are no active wakeup sources.
138 bool "User space wakeup sources interface"
142 Allow user space to create, activate and deactivate wakeup source
143 objects with the help of a sysfs-based interface.
145 config PM_WAKELOCKS_LIMIT
146 int "Maximum number of user space wakeup sources (0 = no limit)"
149 depends on PM_WAKELOCKS
151 config PM_WAKELOCKS_GC
152 bool "Garbage collector for user space wakeup sources"
153 depends on PM_WAKELOCKS
157 bool "Device power management core functionality"
159 Enable functionality allowing I/O devices to be put into energy-saving
160 (low power) states, for example after a specified period of inactivity
161 (autosuspended), and woken up in response to a hardware-generated
162 wake-up event or a driver's request.
164 Hardware support is generally required for this functionality to work
165 and the bus type drivers of the buses the devices are on are
166 responsible for the actual handling of device suspend requests and
170 bool "Power Management Debug Support"
173 This option enables various debugging support in the Power Management
174 code. This is helpful when debugging and reporting PM bugs, like
177 config PM_ADVANCED_DEBUG
178 bool "Extra PM attributes in sysfs for low-level debugging/testing"
181 Add extra sysfs attributes allowing one to access some Power Management
182 fields of device objects from user space. If you are not a kernel
183 developer interested in debugging/testing Power Management, say "no".
185 config PM_TEST_SUSPEND
186 bool "Test suspend/resume and wakealarm during bootup"
187 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
189 This option will let you suspend your machine during bootup, and
190 make it wake up a few seconds later using an RTC wakeup alarm.
191 Enable this with a kernel parameter like "test_suspend=mem".
193 You probably want to have your system's RTC driver statically
194 linked, ensuring that it's available when this test runs.
196 config PM_SLEEP_DEBUG
198 depends on PM_DEBUG && PM_SLEEP
201 bool "Device suspend/resume watchdog"
202 depends on PM_DEBUG && PSTORE
204 Sets up a watchdog timer to capture drivers that are
205 locked up attempting to suspend/resume a device.
206 A detected lockup causes system panic with message
207 captured in pstore device for inspection in subsequent
210 config DPM_WATCHDOG_TIMEOUT
211 int "Watchdog timeout in seconds"
214 depends on DPM_WATCHDOG
219 This enables code to save the last PM event point across
220 reboot. The architecture needs to support this, x86 for
221 example does by saving things in the RTC, see below.
223 The architecture specific code must provide the extern
224 functions from <linux/resume-trace.h> as well as the
225 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
227 The way the information is presented is architecture-
228 dependent, x86 will print the information during a
232 bool "Suspend/resume event tracing"
233 depends on PM_SLEEP_DEBUG
237 This enables some cheesy code to save the last PM event point in the
238 RTC across reboots, so that you can debug a machine that just hangs
239 during suspend (or more commonly, during resume).
241 To use this debugging feature you should attempt to suspend the
242 machine, reboot it and then run
244 dmesg -s 1000000 | grep 'hash matches'
246 CAUTION: this option will cause your machine's real-time clock to be
247 set to an invalid time after a resume.
250 tristate "Advanced Power Management Emulation"
251 depends on PM && SYS_SUPPORTS_APM_EMULATION
253 APM is a BIOS specification for saving power using several different
254 techniques. This is mostly useful for battery powered laptops with
255 APM compliant BIOSes. If you say Y here, the system time will be
256 reset after a RESUME operation, the /proc/apm device will provide
257 battery status information, and user-space programs will receive
258 notification of APM "events" (e.g. battery status change).
260 In order to use APM, you will need supporting software. For location
261 and more information, read <file:Documentation/power/apm-acpi.txt>
262 and the Battery Powered Linux mini-HOWTO, available from
263 <http://www.tldp.org/docs.html#howto>.
265 This driver does not spin down disk drives (see the hdparm(8)
266 manpage ("man 8 hdparm") for that), and it doesn't turn off
267 VESA-compliant "green" monitors.
269 Generally, if you don't have a battery in your machine, there isn't
270 much point in using this driver and you should say N. If you get
271 random kernel OOPSes or reboots that don't seem to be related to
272 anything, try disabling/enabling this option (or disabling/enabling
279 SOCs have a standard set of tuples consisting of frequency and
280 voltage pairs that the device will support per voltage domain. This
281 is called Operating Performance Point or OPP. The actual definitions
282 of OPP varies over silicon within the same family of devices.
284 OPP layer organizes the data internally using device pointers
285 representing individual voltage domains and provides SOC
286 implementations a ready to use framework to manage OPPs.
287 For more information, read <file:Documentation/power/opp.txt>
291 depends on PM && HAVE_CLK
293 config PM_GENERIC_DOMAINS
297 config WQ_POWER_EFFICIENT_DEFAULT
298 bool "Enable workqueue power-efficient mode by default"
302 Per-cpu workqueues are generally preferred because they show
303 better performance thanks to cache locality; unfortunately,
304 per-cpu workqueues tend to be more power hungry than unbound
307 Enabling workqueue.power_efficient kernel parameter makes the
308 per-cpu workqueues which were observed to contribute
309 significantly to power consumption unbound, leading to measurably
310 lower power usage at the cost of small performance overhead.
312 This config option determines whether workqueue.power_efficient
313 is enabled by default.
317 config PM_GENERIC_DOMAINS_SLEEP
319 depends on PM_SLEEP && PM_GENERIC_DOMAINS
321 config PM_GENERIC_DOMAINS_OF
323 depends on PM_GENERIC_DOMAINS && OF