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