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" 24 depends on PM 25 default y 26 ---help--- 27 Support for pm_register() and friends. 28 29 If unsure, say Y. 30 31config PM_DEBUG 32 bool "Power Management Debug Support" 33 depends on PM 34 ---help--- 35 This option enables verbose debugging support in the Power Management 36 code. This is helpful when debugging and reporting various PM bugs, 37 like suspend support. 38 39config PM_TRACE 40 bool "Suspend/resume event tracing" 41 depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL 42 default n 43 ---help--- 44 This enables some cheesy code to save the last PM event point in the 45 RTC across reboots, so that you can debug a machine that just hangs 46 during suspend (or more commonly, during resume). 47 48 To use this debugging feature you should attempt to suspend the machine, 49 then reboot it, then run 50 51 dmesg -s 1000000 | grep 'hash matches' 52 53 CAUTION: this option will cause your machine's real-time clock to be 54 set to an invalid time after a resume. 55 56 57config SOFTWARE_SUSPEND 58 bool "Software Suspend" 59 depends on PM && SWAP && ((X86 && (!SMP || SUSPEND_SMP) && !X86_PAE) || ((FRV || PPC32) && !SMP)) 60 ---help--- 61 Enable the possibility of suspending the machine. 62 It doesn't need ACPI or APM. 63 You may suspend your machine by 'swsusp' or 'shutdown -z <time>' 64 (patch for sysvinit needed). 65 66 It creates an image which is saved in your active swap. Upon next 67 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 68 have it detect the saved image, restore memory state from it, and 69 continue to run as before. If you do not want the previous state to 70 be reloaded, then use the 'noresume' kernel argument. However, note 71 that your partitions will be fsck'd and you must re-mkswap your swap 72 partitions. It does not work with swap files. 73 74 Right now you may boot without resuming and then later resume but 75 in meantime you cannot use those swap partitions/files which were 76 involved in suspending. Also in this case there is a risk that buffers 77 on disk won't match with saved ones. 78 79 For more information take a look at <file:Documentation/power/swsusp.txt>. 80 81 (For now, swsusp is incompatible with PAE aka HIGHMEM_64G on i386. 82 we need identity mapping for resume to work, and that is trivial 83 to get with 4MB pages, but less than trivial on PAE). 84 85config PM_STD_PARTITION 86 string "Default resume partition" 87 depends on SOFTWARE_SUSPEND 88 default "" 89 ---help--- 90 The default resume partition is the partition that the suspend- 91 to-disk implementation will look for a suspended disk image. 92 93 The partition specified here will be different for almost every user. 94 It should be a valid swap partition (at least for now) that is turned 95 on before suspending. 96 97 The partition specified can be overridden by specifying: 98 99 resume=/dev/<other device> 100 101 which will set the resume partition to the device specified. 102 103 Note there is currently not a way to specify which device to save the 104 suspended image to. It will simply pick the first available swap 105 device. 106 107config SUSPEND_SMP 108 bool 109 depends on HOTPLUG_CPU && X86 && PM 110 default y 111