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