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 DISABLE_CONSOLE_SUSPEND 40 bool "Keep console(s) enabled during suspend/resume (DANGEROUS)" 41 depends on PM && PM_DEBUG 42 default n 43 ---help--- 44 This option turns off the console suspend mechanism that prevents 45 debug messages from reaching the console during the suspend/resume 46 operations. This may be helpful when debugging device drivers' 47 suspend/resume routines, but may itself lead to problems, for example 48 if netconsole is used. 49 50config PM_TRACE 51 bool "Suspend/resume event tracing" 52 depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL 53 default n 54 ---help--- 55 This enables some cheesy code to save the last PM event point in the 56 RTC across reboots, so that you can debug a machine that just hangs 57 during suspend (or more commonly, during resume). 58 59 To use this debugging feature you should attempt to suspend the machine, 60 then reboot it, then run 61 62 dmesg -s 1000000 | grep 'hash matches' 63 64 CAUTION: this option will cause your machine's real-time clock to be 65 set to an invalid time after a resume. 66 67config PM_SYSFS_DEPRECATED 68 bool "Driver model /sys/devices/.../power/state files (DEPRECATED)" 69 depends on PM && SYSFS 70 default n 71 help 72 The driver model started out with a sysfs file intended to provide 73 a userspace hook for device power management. This feature has never 74 worked very well, except for limited testing purposes, and so it will 75 be removed. It's not clear that a generic mechanism could really 76 handle the wide variability of device power states; any replacements 77 are likely to be bus or driver specific. 78 79config SOFTWARE_SUSPEND 80 bool "Software Suspend" 81 depends on PM && SWAP && ((X86 && (!SMP || SUSPEND_SMP)) || ((FRV || PPC32) && !SMP)) 82 ---help--- 83 Enable the possibility of suspending the machine. 84 It doesn't need ACPI or APM. 85 You may suspend your machine by 'swsusp' or 'shutdown -z <time>' 86 (patch for sysvinit needed). 87 88 It creates an image which is saved in your active swap. Upon next 89 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 90 have it detect the saved image, restore memory state from it, and 91 continue to run as before. If you do not want the previous state to 92 be reloaded, then use the 'noresume' kernel argument. However, note 93 that your partitions will be fsck'd and you must re-mkswap your swap 94 partitions. It does not work with swap files. 95 96 Right now you may boot without resuming and then later resume but 97 in meantime you cannot use those swap partitions/files which were 98 involved in suspending. Also in this case there is a risk that buffers 99 on disk won't match with saved ones. 100 101 For more information take a look at <file:Documentation/power/swsusp.txt>. 102 103 (For now, swsusp is incompatible with PAE aka HIGHMEM_64G on i386. 104 we need identity mapping for resume to work, and that is trivial 105 to get with 4MB pages, but less than trivial on PAE). 106 107config PM_STD_PARTITION 108 string "Default resume partition" 109 depends on SOFTWARE_SUSPEND 110 default "" 111 ---help--- 112 The default resume partition is the partition that the suspend- 113 to-disk implementation will look for a suspended disk image. 114 115 The partition specified here will be different for almost every user. 116 It should be a valid swap partition (at least for now) that is turned 117 on before suspending. 118 119 The partition specified can be overridden by specifying: 120 121 resume=/dev/<other device> 122 123 which will set the resume partition to the device specified. 124 125 Note there is currently not a way to specify which device to save the 126 suspended image to. It will simply pick the first available swap 127 device. 128 129config SUSPEND_SMP 130 bool 131 depends on HOTPLUG_CPU && X86 && PM 132 default y 133