1config PM 2 bool "Power Management support" 3 depends on !IA64_HP_SIM 4 ---help--- 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. 10 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>. 17 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. 21 22config PM_LEGACY 23 bool "Legacy Power Management API (DEPRECATED)" 24 depends on PM 25 default n 26 ---help--- 27 Support for pm_register() and friends. This old API is obsoleted 28 by the driver model. 29 30 If unsure, say N. 31 32config PM_DEBUG 33 bool "Power Management Debug Support" 34 depends on PM 35 ---help--- 36 This option enables various debugging support in the Power Management 37 code. This is helpful when debugging and reporting PM bugs, like 38 suspend support. 39 40config PM_VERBOSE 41 bool "Verbose Power Management debugging" 42 depends on PM_DEBUG 43 default n 44 ---help--- 45 This option enables verbose messages from the Power Management code. 46 47config DISABLE_CONSOLE_SUSPEND 48 bool "Keep console(s) enabled during suspend/resume (DANGEROUS)" 49 depends on PM_DEBUG && PM_SLEEP 50 default n 51 ---help--- 52 This option turns off the console suspend mechanism that prevents 53 debug messages from reaching the console during the suspend/resume 54 operations. This may be helpful when debugging device drivers' 55 suspend/resume routines, but may itself lead to problems, for example 56 if netconsole is used. 57 58config PM_TRACE 59 bool "Suspend/resume event tracing" 60 depends on PM_DEBUG && X86 && PM_SLEEP && EXPERIMENTAL 61 default n 62 ---help--- 63 This enables some cheesy code to save the last PM event point in the 64 RTC across reboots, so that you can debug a machine that just hangs 65 during suspend (or more commonly, during resume). 66 67 To use this debugging feature you should attempt to suspend the machine, 68 then reboot it, then run 69 70 dmesg -s 1000000 | grep 'hash matches' 71 72 CAUTION: this option will cause your machine's real-time clock to be 73 set to an invalid time after a resume. 74 75config PM_SLEEP_SMP 76 bool 77 depends on SUSPEND_SMP_POSSIBLE || HIBERNATION_SMP_POSSIBLE 78 depends on PM_SLEEP 79 select HOTPLUG_CPU 80 default y 81 82config PM_SLEEP 83 bool 84 depends on SUSPEND || HIBERNATION 85 default y 86 87config SUSPEND_UP_POSSIBLE 88 bool 89 depends on (X86 && !X86_VOYAGER) || PPC || ARM || BLACKFIN || MIPS \ 90 || SUPERH || FRV 91 depends on !SMP 92 default y 93 94config SUSPEND_SMP_POSSIBLE 95 bool 96 depends on (X86 && !X86_VOYAGER) \ 97 || (PPC && (PPC_PSERIES || PPC_PMAC)) || ARM 98 depends on SMP 99 default y 100 101config SUSPEND 102 bool "Suspend to RAM and standby" 103 depends on PM 104 depends on SUSPEND_UP_POSSIBLE || SUSPEND_SMP_POSSIBLE 105 default y 106 ---help--- 107 Allow the system to enter sleep states in which main memory is 108 powered and thus its contents are preserved, such as the 109 suspend-to-RAM state (i.e. the ACPI S3 state). 110 111config HIBERNATION_UP_POSSIBLE 112 bool 113 depends on X86 || PPC64_SWSUSP || PPC32 114 depends on !SMP 115 default y 116 117config HIBERNATION_SMP_POSSIBLE 118 bool 119 depends on (X86 && !X86_VOYAGER) || PPC64_SWSUSP 120 depends on SMP 121 default y 122 123config HIBERNATION 124 bool "Hibernation (aka 'suspend to disk')" 125 depends on PM && SWAP 126 depends on HIBERNATION_UP_POSSIBLE || HIBERNATION_SMP_POSSIBLE 127 ---help--- 128 Enable the suspend to disk (STD) functionality, which is usually 129 called "hibernation" in user interfaces. STD checkpoints the 130 system and powers it off; and restores that checkpoint on reboot. 131 132 You can suspend your machine with 'echo disk > /sys/power/state'. 133 Alternatively, you can use the additional userland tools available 134 from <http://suspend.sf.net>. 135 136 In principle it does not require ACPI or APM, although for example 137 ACPI will be used for the final steps when it is available. One 138 of the reasons to use software suspend is that the firmware hooks 139 for suspend states like suspend-to-RAM (STR) often don't work very 140 well with Linux. 141 142 It creates an image which is saved in your active swap. Upon the next 143 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 144 have it detect the saved image, restore memory state from it, and 145 continue to run as before. If you do not want the previous state to 146 be reloaded, then use the 'noresume' kernel command line argument. 147 Note, however, that fsck will be run on your filesystems and you will 148 need to run mkswap against the swap partition used for the suspend. 149 150 It also works with swap files to a limited extent (for details see 151 <file:Documentation/power/swsusp-and-swap-files.txt>). 152 153 Right now you may boot without resuming and resume later but in the 154 meantime you cannot use the swap partition(s)/file(s) involved in 155 suspending. Also in this case you must not use the filesystems 156 that were mounted before the suspend. In particular, you MUST NOT 157 MOUNT any journaled filesystems mounted before the suspend or they 158 will get corrupted in a nasty way. 159 160 For more information take a look at <file:Documentation/power/swsusp.txt>. 161 162config PM_STD_PARTITION 163 string "Default resume partition" 164 depends on HIBERNATION 165 default "" 166 ---help--- 167 The default resume partition is the partition that the suspend- 168 to-disk implementation will look for a suspended disk image. 169 170 The partition specified here will be different for almost every user. 171 It should be a valid swap partition (at least for now) that is turned 172 on before suspending. 173 174 The partition specified can be overridden by specifying: 175 176 resume=/dev/<other device> 177 178 which will set the resume partition to the device specified. 179 180 Note there is currently not a way to specify which device to save the 181 suspended image to. It will simply pick the first available swap 182 device. 183 184config APM_EMULATION 185 tristate "Advanced Power Management Emulation" 186 depends on PM && SYS_SUPPORTS_APM_EMULATION 187 help 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). 194 195 In order to use APM, you will need supporting software. For location 196 and more information, read <file:Documentation/pm.txt> and the 197 Battery Powered Linux mini-HOWTO, available from 198 <http://www.tldp.org/docs.html#howto>. 199 200 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. 203 204 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 208 APM in your BIOS). 209