2 bool "Power Management support"
3 depends on !IA64_HP_SIM
5 "Power Management" means that parts of your computer are shut
6 off or put into a power conserving "sleep" mode if they are not
7 being used. There are two competing standards for doing this: APM
8 and ACPI. If you want to use either one, say Y here and then also
9 to the requisite support below.
11 Power Management is most important for battery powered laptop
12 computers; if you have a laptop, check out the Linux Laptop home
13 page on the WWW at <http://www.linux-on-laptops.com/> or
14 Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/>
15 and the Battery Powered Linux mini-HOWTO, available from
16 <http://www.tldp.org/docs.html#howto>.
18 Note that, even if you say N here, Linux on the x86 architecture
19 will issue the hlt instruction if nothing is to be done, thereby
20 sending the processor to sleep and saving power.
23 bool "Legacy Power Management API (DEPRECATED)"
27 Support for pm_register() and friends. This old API is obsoleted
33 bool "Power Management Debug Support"
36 This option enables various debugging support in the Power Management
37 code. This is helpful when debugging and reporting PM bugs, like
41 bool "Verbose Power Management debugging"
45 This option enables verbose messages from the Power Management code.
49 depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL
54 This enables code to save the last PM event point across
55 reboot. The architecture needs to support this, x86 for
56 example does by saving things in the RTC, see below.
58 The architecture specific code must provide the extern
59 functions from <linux/resume-trace.h> as well as the
60 <asm/resume-trace.h> header with a TRACE_RESUME() macro.
62 The way the information is presented is architecture-
63 dependent, x86 will print the information during a
67 bool "Suspend/resume event tracing"
68 depends on CAN_PM_TRACE
73 This enables some cheesy code to save the last PM event point in the
74 RTC across reboots, so that you can debug a machine that just hangs
75 during suspend (or more commonly, during resume).
77 To use this debugging feature you should attempt to suspend the machine,
78 then reboot it, then run
80 dmesg -s 1000000 | grep 'hash matches'
82 CAUTION: this option will cause your machine's real-time clock to be
83 set to an invalid time after a resume.
88 depends on SUSPEND_SMP_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
95 depends on SUSPEND || HIBERNATION
98 config SUSPEND_UP_POSSIBLE
100 depends on (X86 && !X86_VOYAGER) || PPC || ARM || BLACKFIN || MIPS \
105 config SUSPEND_SMP_POSSIBLE
107 depends on (X86 && !X86_VOYAGER) \
108 || (PPC && (PPC_PSERIES || PPC_PMAC)) || ARM
113 bool "Suspend to RAM and standby"
115 depends on SUSPEND_UP_POSSIBLE || SUSPEND_SMP_POSSIBLE
118 Allow the system to enter sleep states in which main memory is
119 powered and thus its contents are preserved, such as the
120 suspend-to-RAM state (i.e. the ACPI S3 state).
123 bool "Hibernation (aka 'suspend to disk')"
124 depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
126 Enable the suspend to disk (STD) functionality, which is usually
127 called "hibernation" in user interfaces. STD checkpoints the
128 system and powers it off; and restores that checkpoint on reboot.
130 You can suspend your machine with 'echo disk > /sys/power/state'.
131 Alternatively, you can use the additional userland tools available
132 from <http://suspend.sf.net>.
134 In principle it does not require ACPI or APM, although for example
135 ACPI will be used for the final steps when it is available. One
136 of the reasons to use software suspend is that the firmware hooks
137 for suspend states like suspend-to-RAM (STR) often don't work very
140 It creates an image which is saved in your active swap. Upon the next
141 boot, pass the 'resume=/dev/swappartition' argument to the kernel to
142 have it detect the saved image, restore memory state from it, and
143 continue to run as before. If you do not want the previous state to
144 be reloaded, then use the 'noresume' kernel command line argument.
145 Note, however, that fsck will be run on your filesystems and you will
146 need to run mkswap against the swap partition used for the suspend.
148 It also works with swap files to a limited extent (for details see
149 <file:Documentation/power/swsusp-and-swap-files.txt>).
151 Right now you may boot without resuming and resume later but in the
152 meantime you cannot use the swap partition(s)/file(s) involved in
153 suspending. Also in this case you must not use the filesystems
154 that were mounted before the suspend. In particular, you MUST NOT
155 MOUNT any journaled filesystems mounted before the suspend or they
156 will get corrupted in a nasty way.
158 For more information take a look at <file:Documentation/power/swsusp.txt>.
160 config PM_STD_PARTITION
161 string "Default resume partition"
162 depends on HIBERNATION
165 The default resume partition is the partition that the suspend-
166 to-disk implementation will look for a suspended disk image.
168 The partition specified here will be different for almost every user.
169 It should be a valid swap partition (at least for now) that is turned
170 on before suspending.
172 The partition specified can be overridden by specifying:
174 resume=/dev/<other device>
176 which will set the resume partition to the device specified.
178 Note there is currently not a way to specify which device to save the
179 suspended image to. It will simply pick the first available swap
183 tristate "Advanced Power Management Emulation"
184 depends on PM && SYS_SUPPORTS_APM_EMULATION
186 APM is a BIOS specification for saving power using several different
187 techniques. This is mostly useful for battery powered laptops with
188 APM compliant BIOSes. If you say Y here, the system time will be
189 reset after a RESUME operation, the /proc/apm device will provide
190 battery status information, and user-space programs will receive
191 notification of APM "events" (e.g. battery status change).
193 In order to use APM, you will need supporting software. For location
194 and more information, read <file:Documentation/pm.txt> and the
195 Battery Powered Linux mini-HOWTO, available from
196 <http://www.tldp.org/docs.html#howto>.
198 This driver does not spin down disk drives (see the hdparm(8)
199 manpage ("man 8 hdparm") for that), and it doesn't turn off
200 VESA-compliant "green" monitors.
202 Generally, if you don't have a battery in your machine, there isn't
203 much point in using this driver and you should say N. If you get
204 random kernel OOPSes or reboots that don't seem to be related to
205 anything, try disabling/enabling this option (or disabling/enabling