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 PM_TRACE 48 bool "Suspend/resume event tracing" 49 depends on PM_DEBUG && X86 && PM_SLEEP && EXPERIMENTAL 50 default n 51 ---help--- 52 This enables some cheesy code to save the last PM event point in the 53 RTC across reboots, so that you can debug a machine that just hangs 54 during suspend (or more commonly, during resume). 55 56 To use this debugging feature you should attempt to suspend the machine, 57 then reboot it, then run 58 59 dmesg -s 1000000 | grep 'hash matches' 60 61 CAUTION: this option will cause your machine's real-time clock to be 62 set to an invalid time after a resume. 63 64config PM_SLEEP_SMP 65 bool 66 depends on SUSPEND_SMP_POSSIBLE || HIBERNATION_SMP_POSSIBLE 67 depends on PM_SLEEP 68 select HOTPLUG_CPU 69 default y 70 71config PM_SLEEP 72 bool 73 depends on SUSPEND || HIBERNATION 74 default y 75 76config SUSPEND_UP_POSSIBLE 77 bool 78 depends on (X86 && !X86_VOYAGER) || PPC || ARM || BLACKFIN || MIPS \ 79 || SUPERH || FRV 80 depends on !SMP 81 default y 82 83config SUSPEND_SMP_POSSIBLE 84 bool 85 depends on (X86 && !X86_VOYAGER) \ 86 || (PPC && (PPC_PSERIES || PPC_PMAC)) || ARM 87 depends on SMP 88 default y 89 90config SUSPEND 91 bool "Suspend to RAM and standby" 92 depends on PM 93 depends on SUSPEND_UP_POSSIBLE || SUSPEND_SMP_POSSIBLE 94 default y 95 ---help--- 96 Allow the system to enter sleep states in which main memory is 97 powered and thus its contents are preserved, such as the 98 suspend-to-RAM state (i.e. the ACPI S3 state). 99 100config HIBERNATION_UP_POSSIBLE 101 bool 102 depends on X86 || PPC64_SWSUSP || PPC32 103 depends on !SMP 104 default y 105 106config HIBERNATION_SMP_POSSIBLE 107 bool 108 depends on (X86 && !X86_VOYAGER) || PPC64_SWSUSP 109 depends on SMP 110 default y 111 112config HIBERNATION 113 bool "Hibernation (aka 'suspend to disk')" 114 depends on PM && SWAP 115 depends on HIBERNATION_UP_POSSIBLE || HIBERNATION_SMP_POSSIBLE 116 ---help--- 117 Enable the suspend to disk (STD) functionality, which is usually 118 called "hibernation" in user interfaces. STD checkpoints the 119 system and powers it off; and restores that checkpoint on reboot. 120 121 You can suspend your machine with 'echo disk > /sys/power/state'. 122 Alternatively, you can use the additional userland tools available 123 from <http://suspend.sf.net>. 124 125 In principle it does not require ACPI or APM, although for example 126 ACPI will be used for the final steps when it is available. One 127 of the reasons to use software suspend is that the firmware hooks 128 for suspend states like suspend-to-RAM (STR) often don't work very 129 well with Linux. 130 131 It creates an image which is saved in your active swap. Upon the next 132 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 133 have it detect the saved image, restore memory state from it, and 134 continue to run as before. If you do not want the previous state to 135 be reloaded, then use the 'noresume' kernel command line argument. 136 Note, however, that fsck will be run on your filesystems and you will 137 need to run mkswap against the swap partition used for the suspend. 138 139 It also works with swap files to a limited extent (for details see 140 <file:Documentation/power/swsusp-and-swap-files.txt>). 141 142 Right now you may boot without resuming and resume later but in the 143 meantime you cannot use the swap partition(s)/file(s) involved in 144 suspending. Also in this case you must not use the filesystems 145 that were mounted before the suspend. In particular, you MUST NOT 146 MOUNT any journaled filesystems mounted before the suspend or they 147 will get corrupted in a nasty way. 148 149 For more information take a look at <file:Documentation/power/swsusp.txt>. 150 151config PM_STD_PARTITION 152 string "Default resume partition" 153 depends on HIBERNATION 154 default "" 155 ---help--- 156 The default resume partition is the partition that the suspend- 157 to-disk implementation will look for a suspended disk image. 158 159 The partition specified here will be different for almost every user. 160 It should be a valid swap partition (at least for now) that is turned 161 on before suspending. 162 163 The partition specified can be overridden by specifying: 164 165 resume=/dev/<other device> 166 167 which will set the resume partition to the device specified. 168 169 Note there is currently not a way to specify which device to save the 170 suspended image to. It will simply pick the first available swap 171 device. 172 173config APM_EMULATION 174 tristate "Advanced Power Management Emulation" 175 depends on PM && SYS_SUPPORTS_APM_EMULATION 176 help 177 APM is a BIOS specification for saving power using several different 178 techniques. This is mostly useful for battery powered laptops with 179 APM compliant BIOSes. If you say Y here, the system time will be 180 reset after a RESUME operation, the /proc/apm device will provide 181 battery status information, and user-space programs will receive 182 notification of APM "events" (e.g. battery status change). 183 184 In order to use APM, you will need supporting software. For location 185 and more information, read <file:Documentation/pm.txt> and the 186 Battery Powered Linux mini-HOWTO, available from 187 <http://www.tldp.org/docs.html#howto>. 188 189 This driver does not spin down disk drives (see the hdparm(8) 190 manpage ("man 8 hdparm") for that), and it doesn't turn off 191 VESA-compliant "green" monitors. 192 193 Generally, if you don't have a battery in your machine, there isn't 194 much point in using this driver and you should say N. If you get 195 random kernel OOPSes or reboots that don't seem to be related to 196 anything, try disabling/enabling this option (or disabling/enabling 197 APM in your BIOS). 198