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