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 verbose debugging support in the Power Management 37 code. This is helpful when debugging and reporting various PM bugs, 38 like suspend support. 39 40config DISABLE_CONSOLE_SUSPEND 41 bool "Keep console(s) enabled during suspend/resume (DANGEROUS)" 42 depends on PM && PM_DEBUG 43 default n 44 ---help--- 45 This option turns off the console suspend mechanism that prevents 46 debug messages from reaching the console during the suspend/resume 47 operations. This may be helpful when debugging device drivers' 48 suspend/resume routines, but may itself lead to problems, for example 49 if netconsole is used. 50 51config PM_TRACE 52 bool "Suspend/resume event tracing" 53 depends on PM && PM_DEBUG && X86_32 && EXPERIMENTAL 54 default n 55 ---help--- 56 This enables some cheesy code to save the last PM event point in the 57 RTC across reboots, so that you can debug a machine that just hangs 58 during suspend (or more commonly, during resume). 59 60 To use this debugging feature you should attempt to suspend the machine, 61 then reboot it, then run 62 63 dmesg -s 1000000 | grep 'hash matches' 64 65 CAUTION: this option will cause your machine's real-time clock to be 66 set to an invalid time after a resume. 67 68config PM_SYSFS_DEPRECATED 69 bool "Driver model /sys/devices/.../power/state files (DEPRECATED)" 70 depends on PM && SYSFS 71 default n 72 help 73 The driver model started out with a sysfs file intended to provide 74 a userspace hook for device power management. This feature has never 75 worked very well, except for limited testing purposes, and so it will 76 be removed. It's not clear that a generic mechanism could really 77 handle the wide variability of device power states; any replacements 78 are likely to be bus or driver specific. 79 80config SOFTWARE_SUSPEND 81 bool "Software Suspend" 82 depends on PM && SWAP && ((X86 && (!SMP || SUSPEND_SMP)) || ((FRV || PPC32) && !SMP)) 83 ---help--- 84 Enable the possibility of suspending the machine. 85 It doesn't need ACPI or APM. 86 You may suspend your machine by 'swsusp' or 'shutdown -z <time>' 87 (patch for sysvinit needed). 88 89 It creates an image which is saved in your active swap. Upon next 90 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 91 have it detect the saved image, restore memory state from it, and 92 continue to run as before. If you do not want the previous state to 93 be reloaded, then use the 'noresume' kernel argument. However, note 94 that your partitions will be fsck'd and you must re-mkswap your swap 95 partitions. It does not work with swap files. 96 97 Right now you may boot without resuming and then later resume but 98 in meantime you cannot use those swap partitions/files which were 99 involved in suspending. Also in this case there is a risk that buffers 100 on disk won't match with saved ones. 101 102 For more information take a look at <file:Documentation/power/swsusp.txt>. 103 104 (For now, swsusp is incompatible with PAE aka HIGHMEM_64G on i386. 105 we need identity mapping for resume to work, and that is trivial 106 to get with 4MB pages, but less than trivial on PAE). 107 108config PM_STD_PARTITION 109 string "Default resume partition" 110 depends on SOFTWARE_SUSPEND 111 default "" 112 ---help--- 113 The default resume partition is the partition that the suspend- 114 to-disk implementation will look for a suspended disk image. 115 116 The partition specified here will be different for almost every user. 117 It should be a valid swap partition (at least for now) that is turned 118 on before suspending. 119 120 The partition specified can be overridden by specifying: 121 122 resume=/dev/<other device> 123 124 which will set the resume partition to the device specified. 125 126 Note there is currently not a way to specify which device to save the 127 suspended image to. It will simply pick the first available swap 128 device. 129 130config SUSPEND_SMP 131 bool 132 depends on HOTPLUG_CPU && X86 && PM 133 default y 134