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.
22 bool "Hibernation (aka 'suspend to disk')"
23 depends on SWAP && ARCH_HIBERNATION_POSSIBLE
27 Enable the suspend to disk (STD) functionality, which is usually
28 called "hibernation" in user interfaces. STD checkpoints the
29 system and powers it off; and restores that checkpoint on reboot.
31 You can suspend your machine with 'echo disk > /sys/power/state'
32 after placing resume=/dev/swappartition on the kernel command line
33 in your bootloader's configuration file.
35 Alternatively, you can use the additional userland tools available
36 from <http://suspend.sf.net>.
38 In principle it does not require ACPI or APM, although for example
39 ACPI will be used for the final steps when it is available. One
40 of the reasons to use software suspend is that the firmware hooks
41 for suspend states like suspend-to-RAM (STR) often don't work very
44 It creates an image which is saved in your active swap. Upon the next
45 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
46 have it detect the saved image, restore memory state from it, and
47 continue to run as before. If you do not want the previous state to
48 be reloaded, then use the 'noresume' kernel command line argument.
49 Note, however, that fsck will be run on your filesystems and you will
50 need to run mkswap against the swap partition used for the suspend.
52 It also works with swap files to a limited extent (for details see
53 <file:Documentation/power/swsusp-and-swap-files.txt>).
55 Right now you may boot without resuming and resume later but in the
56 meantime you cannot use the swap partition(s)/file(s) involved in
57 suspending. Also in this case you must not use the filesystems
58 that were mounted before the suspend. In particular, you MUST NOT
59 MOUNT any journaled filesystems mounted before the suspend or they
60 will get corrupted in a nasty way.
62 For more information take a look at <file:Documentation/power/swsusp.txt>.
64 config PM_STD_PARTITION
65 string "Default resume partition"
66 depends on HIBERNATION
69 The default resume partition is the partition that the suspend-
70 to-disk implementation will look for a suspended disk image.
72 The partition specified here will be different for almost every user.
73 It should be a valid swap partition (at least for now) that is turned
76 The partition specified can be overridden by specifying:
78 resume=/dev/<other device>
80 which will set the resume partition to the device specified.
82 Note there is currently not a way to specify which device to save the
83 suspended image to. It will simply pick the first available swap
88 depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
94 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
101 bool "Run-time PM core functionality"
102 depends on !IA64_HP_SIM
104 Enable functionality allowing I/O devices to be put into energy-saving
105 (low power) states at run time (or autosuspended) after a specified
106 period of inactivity and woken up in response to a hardware-generated
107 wake-up event or a driver's request.
109 Hardware support is generally required for this functionality to work
110 and the bus type drivers of the buses the devices are on are
111 responsible for the actual handling of the autosuspend requests and
116 depends on PM_SLEEP || PM_RUNTIME
120 bool "Power Management Debug Support"
123 This option enables various debugging support in the Power Management
124 code. This is helpful when debugging and reporting PM bugs, like
128 bool "Verbose Power Management debugging"
132 This option enables verbose messages from the Power Management code.
134 config PM_ADVANCED_DEBUG
135 bool "Extra PM attributes in sysfs for low-level debugging/testing"
139 Add extra sysfs attributes allowing one to access some Power Management
140 fields of device objects from user space. If you are not a kernel
141 developer interested in debugging/testing Power Management, say "no".
143 config PM_SLEEP_ADVANCED_DEBUG
145 depends on PM_ADVANCED_DEBUG
148 config PM_TEST_SUSPEND
149 bool "Test suspend/resume and wakealarm during bootup"
150 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
152 This option will let you suspend your machine during bootup, and
153 make it wake up a few seconds later using an RTC wakeup alarm.
154 Enable this with a kernel parameter like "test_suspend=mem".
156 You probably want to have your system's RTC driver statically
157 linked, ensuring that it's available when this test runs.
161 depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL
166 This enables code to save the last PM event point across
167 reboot. The architecture needs to support this, x86 for
168 example does by saving things in the RTC, see below.
170 The architecture specific code must provide the extern
171 functions from <linux/resume-trace.h> as well as the
172 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
174 The way the information is presented is architecture-
175 dependent, x86 will print the information during a
179 bool "Suspend/resume event tracing"
180 depends on CAN_PM_TRACE
185 This enables some cheesy code to save the last PM event point in the
186 RTC across reboots, so that you can debug a machine that just hangs
187 during suspend (or more commonly, during resume).
189 To use this debugging feature you should attempt to suspend the
190 machine, reboot it and then run
192 dmesg -s 1000000 | grep 'hash matches'
194 CAUTION: this option will cause your machine's real-time clock to be
195 set to an invalid time after a resume.
198 tristate "Advanced Power Management Emulation"
199 depends on PM && SYS_SUPPORTS_APM_EMULATION
201 APM is a BIOS specification for saving power using several different
202 techniques. This is mostly useful for battery powered laptops with
203 APM compliant BIOSes. If you say Y here, the system time will be
204 reset after a RESUME operation, the /proc/apm device will provide
205 battery status information, and user-space programs will receive
206 notification of APM "events" (e.g. battery status change).
208 In order to use APM, you will need supporting software. For location
209 and more information, read <file:Documentation/power/pm.txt> and the
210 Battery Powered Linux mini-HOWTO, available from
211 <http://www.tldp.org/docs.html#howto>.
213 This driver does not spin down disk drives (see the hdparm(8)
214 manpage ("man 8 hdparm") for that), and it doesn't turn off
215 VESA-compliant "green" monitors.
217 Generally, if you don't have a battery in your machine, there isn't
218 much point in using this driver and you should say N. If you get
219 random kernel OOPSes or reboots that don't seem to be related to
220 anything, try disabling/enabling this option (or disabling/enabling
227 bool "Operating Performance Point (OPP) Layer library"
228 depends on ARCH_HAS_OPP
230 SOCs have a standard set of tuples consisting of frequency and
231 voltage pairs that the device will support per voltage domain. This
232 is called Operating Performance Point or OPP. The actual definitions
233 of OPP varies over silicon within the same family of devices.
235 OPP layer organizes the data internally using device pointers
236 representing individual voltage domains and provides SOC
237 implementations a ready to use framework to manage OPPs.
238 For more information, read <file:Documentation/power/opp.txt>