3 depends on PM_SLEEP || PM_RUNTIME
7 bool "Power Management Debug Support"
10 This option enables various debugging support in the Power Management
11 code. This is helpful when debugging and reporting PM bugs, like
14 config PM_ADVANCED_DEBUG
15 bool "Extra PM attributes in sysfs for low-level debugging/testing"
19 Add extra sysfs attributes allowing one to access some Power Management
20 fields of device objects from user space. If you are not a kernel
21 developer interested in debugging/testing Power Management, say "no".
24 bool "Verbose Power Management debugging"
28 This option enables verbose messages from the Power Management code.
32 depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL
37 This enables code to save the last PM event point across
38 reboot. The architecture needs to support this, x86 for
39 example does by saving things in the RTC, see below.
41 The architecture specific code must provide the extern
42 functions from <linux/resume-trace.h> as well as the
43 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
45 The way the information is presented is architecture-
46 dependent, x86 will print the information during a
50 bool "Suspend/resume event tracing"
51 depends on CAN_PM_TRACE
56 This enables some cheesy code to save the last PM event point in the
57 RTC across reboots, so that you can debug a machine that just hangs
58 during suspend (or more commonly, during resume).
60 To use this debugging feature you should attempt to suspend the
61 machine, reboot it and then run
63 dmesg -s 1000000 | grep 'hash matches'
65 CAUTION: this option will cause your machine's real-time clock to be
66 set to an invalid time after a resume.
71 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
79 depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
82 config PM_SLEEP_ADVANCED_DEBUG
84 depends on PM_ADVANCED_DEBUG
88 bool "Suspend to RAM and standby"
89 depends on ARCH_SUSPEND_POSSIBLE
92 Allow the system to enter sleep states in which main memory is
93 powered and thus its contents are preserved, such as the
94 suspend-to-RAM state (e.g. the ACPI S3 state).
96 config PM_TEST_SUSPEND
97 bool "Test suspend/resume and wakealarm during bootup"
98 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
100 This option will let you suspend your machine during bootup, and
101 make it wake up a few seconds later using an RTC wakeup alarm.
102 Enable this with a kernel parameter like "test_suspend=mem".
104 You probably want to have your system's RTC driver statically
105 linked, ensuring that it's available when this test runs.
107 config SUSPEND_FREEZER
108 bool "Enable freezer for suspend to RAM/standby" \
109 if ARCH_WANTS_FREEZER_CONTROL || BROKEN
113 This allows you to turn off the freezer for suspend. If this is
114 done, no tasks are frozen for suspend to RAM/standby.
116 Turning OFF this setting is NOT recommended! If in doubt, say Y.
119 bool "Hibernation (aka 'suspend to disk')"
120 depends on SWAP && ARCH_HIBERNATION_POSSIBLE
122 select LZO_DECOMPRESS
124 Enable the suspend to disk (STD) functionality, which is usually
125 called "hibernation" in user interfaces. STD checkpoints the
126 system and powers it off; and restores that checkpoint on reboot.
128 You can suspend your machine with 'echo disk > /sys/power/state'
129 after placing resume=/dev/swappartition on the kernel command line
130 in your bootloader's configuration file.
132 Alternatively, you can use the additional userland tools available
133 from <http://suspend.sf.net>.
135 In principle it does not require ACPI or APM, although for example
136 ACPI will be used for the final steps when it is available. One
137 of the reasons to use software suspend is that the firmware hooks
138 for suspend states like suspend-to-RAM (STR) often don't work very
141 It creates an image which is saved in your active swap. Upon the next
142 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
143 have it detect the saved image, restore memory state from it, and
144 continue to run as before. If you do not want the previous state to
145 be reloaded, then use the 'noresume' kernel command line argument.
146 Note, however, that fsck will be run on your filesystems and you will
147 need to run mkswap against the swap partition used for the suspend.
149 It also works with swap files to a limited extent (for details see
150 <file:Documentation/power/swsusp-and-swap-files.txt>).
152 Right now you may boot without resuming and resume later but in the
153 meantime you cannot use the swap partition(s)/file(s) involved in
154 suspending. Also in this case you must not use the filesystems
155 that were mounted before the suspend. In particular, you MUST NOT
156 MOUNT any journaled filesystems mounted before the suspend or they
157 will get corrupted in a nasty way.
159 For more information take a look at <file:Documentation/power/swsusp.txt>.
161 config PM_STD_PARTITION
162 string "Default resume partition"
163 depends on HIBERNATION
166 The default resume partition is the partition that the suspend-
167 to-disk implementation will look for a suspended disk image.
169 The partition specified here will be different for almost every user.
170 It should be a valid swap partition (at least for now) that is turned
171 on before suspending.
173 The partition specified can be overridden by specifying:
175 resume=/dev/<other device>
177 which will set the resume partition to the device specified.
179 Note there is currently not a way to specify which device to save the
180 suspended image to. It will simply pick the first available swap
184 tristate "Advanced Power Management Emulation"
185 depends on PM && SYS_SUPPORTS_APM_EMULATION
187 APM is a BIOS specification for saving power using several different
188 techniques. This is mostly useful for battery powered laptops with
189 APM compliant BIOSes. If you say Y here, the system time will be
190 reset after a RESUME operation, the /proc/apm device will provide
191 battery status information, and user-space programs will receive
192 notification of APM "events" (e.g. battery status change).
194 In order to use APM, you will need supporting software. For location
195 and more information, read <file:Documentation/power/pm.txt> and the
196 Battery Powered Linux mini-HOWTO, available from
197 <http://www.tldp.org/docs.html#howto>.
199 This driver does not spin down disk drives (see the hdparm(8)
200 manpage ("man 8 hdparm") for that), and it doesn't turn off
201 VESA-compliant "green" monitors.
203 Generally, if you don't have a battery in your machine, there isn't
204 much point in using this driver and you should say N. If you get
205 random kernel OOPSes or reboots that don't seem to be related to
206 anything, try disabling/enabling this option (or disabling/enabling
210 bool "Run-time PM core functionality"
211 depends on !IA64_HP_SIM
213 Enable functionality allowing I/O devices to be put into energy-saving
214 (low power) states at run time (or autosuspended) after a specified
215 period of inactivity and woken up in response to a hardware-generated
216 wake-up event or a driver's request.
218 Hardware support is generally required for this functionality to work
219 and the bus type drivers of the buses the devices are on are
220 responsible for the actual handling of the autosuspend requests and
225 depends on PM_SLEEP || PM_RUNTIME
232 bool "Operating Performance Point (OPP) Layer library"
233 depends on ARCH_HAS_OPP
235 SOCs have a standard set of tuples consisting of frequency and
236 voltage pairs that the device will support per voltage domain. This
237 is called Operating Performance Point or OPP. The actual definitions
238 of OPP varies over silicon within the same family of devices.
240 OPP layer organizes the data internally using device pointers
241 representing individual voltage domains and provides SOC
242 implementations a ready to use framework to manage OPPs.
243 For more information, read <file:Documentation/power/opp.txt>