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