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_DEBUG 23 bool "Power Management Debug Support" 24 depends on PM 25 ---help--- 26 This option enables various debugging support in the Power Management 27 code. This is helpful when debugging and reporting PM bugs, like 28 suspend support. 29 30config PM_ADVANCED_DEBUG 31 bool "Extra PM attributes in sysfs for low-level debugging/testing" 32 depends on PM_DEBUG 33 default n 34 ---help--- 35 Add extra sysfs attributes allowing one to access some Power Management 36 fields of device objects from user space. If you are not a kernel 37 developer interested in debugging/testing Power Management, say "no". 38 39config PM_VERBOSE 40 bool "Verbose Power Management debugging" 41 depends on PM_DEBUG 42 default n 43 ---help--- 44 This option enables verbose messages from the Power Management code. 45 46config CAN_PM_TRACE 47 def_bool y 48 depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL 49 50config PM_TRACE 51 bool 52 help 53 This enables code to save the last PM event point across 54 reboot. The architecture needs to support this, x86 for 55 example does by saving things in the RTC, see below. 56 57 The architecture specific code must provide the extern 58 functions from <linux/resume-trace.h> as well as the 59 <asm/resume-trace.h> header with a TRACE_RESUME() macro. 60 61 The way the information is presented is architecture- 62 dependent, x86 will print the information during a 63 late_initcall. 64 65config PM_TRACE_RTC 66 bool "Suspend/resume event tracing" 67 depends on CAN_PM_TRACE 68 depends on X86 69 select PM_TRACE 70 default n 71 ---help--- 72 This enables some cheesy code to save the last PM event point in the 73 RTC across reboots, so that you can debug a machine that just hangs 74 during suspend (or more commonly, during resume). 75 76 To use this debugging feature you should attempt to suspend the 77 machine, reboot it and then run 78 79 dmesg -s 1000000 | grep 'hash matches' 80 81 CAUTION: this option will cause your machine's real-time clock to be 82 set to an invalid time after a resume. 83 84config PM_SLEEP_SMP 85 bool 86 depends on SMP 87 depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE 88 depends on PM_SLEEP 89 select HOTPLUG_CPU 90 default y 91 92config PM_SLEEP 93 bool 94 depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE 95 default y 96 97config PM_SLEEP_ADVANCED_DEBUG 98 bool 99 depends on PM_ADVANCED_DEBUG 100 default n 101 102config SUSPEND 103 bool "Suspend to RAM and standby" 104 depends on PM && ARCH_SUSPEND_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 (e.g. the ACPI S3 state). 110 111config PM_TEST_SUSPEND 112 bool "Test suspend/resume and wakealarm during bootup" 113 depends on SUSPEND && PM_DEBUG && RTC_CLASS=y 114 ---help--- 115 This option will let you suspend your machine during bootup, and 116 make it wake up a few seconds later using an RTC wakeup alarm. 117 Enable this with a kernel parameter like "test_suspend=mem". 118 119 You probably want to have your system's RTC driver statically 120 linked, ensuring that it's available when this test runs. 121 122config SUSPEND_FREEZER 123 bool "Enable freezer for suspend to RAM/standby" \ 124 if ARCH_WANTS_FREEZER_CONTROL || BROKEN 125 depends on SUSPEND 126 default y 127 help 128 This allows you to turn off the freezer for suspend. If this is 129 done, no tasks are frozen for suspend to RAM/standby. 130 131 Turning OFF this setting is NOT recommended! If in doubt, say Y. 132 133config HIBERNATION_NVS 134 bool 135 136config HIBERNATION 137 bool "Hibernation (aka 'suspend to disk')" 138 depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE 139 select HIBERNATION_NVS if HAS_IOMEM 140 ---help--- 141 Enable the suspend to disk (STD) functionality, which is usually 142 called "hibernation" in user interfaces. STD checkpoints the 143 system and powers it off; and restores that checkpoint on reboot. 144 145 You can suspend your machine with 'echo disk > /sys/power/state' 146 after placing resume=/dev/swappartition on the kernel command line 147 in your bootloader's configuration file. 148 149 Alternatively, you can use the additional userland tools available 150 from <http://suspend.sf.net>. 151 152 In principle it does not require ACPI or APM, although for example 153 ACPI will be used for the final steps when it is available. One 154 of the reasons to use software suspend is that the firmware hooks 155 for suspend states like suspend-to-RAM (STR) often don't work very 156 well with Linux. 157 158 It creates an image which is saved in your active swap. Upon the next 159 boot, pass the 'resume=/dev/swappartition' argument to the kernel to 160 have it detect the saved image, restore memory state from it, and 161 continue to run as before. If you do not want the previous state to 162 be reloaded, then use the 'noresume' kernel command line argument. 163 Note, however, that fsck will be run on your filesystems and you will 164 need to run mkswap against the swap partition used for the suspend. 165 166 It also works with swap files to a limited extent (for details see 167 <file:Documentation/power/swsusp-and-swap-files.txt>). 168 169 Right now you may boot without resuming and resume later but in the 170 meantime you cannot use the swap partition(s)/file(s) involved in 171 suspending. Also in this case you must not use the filesystems 172 that were mounted before the suspend. In particular, you MUST NOT 173 MOUNT any journaled filesystems mounted before the suspend or they 174 will get corrupted in a nasty way. 175 176 For more information take a look at <file:Documentation/power/swsusp.txt>. 177 178config PM_STD_PARTITION 179 string "Default resume partition" 180 depends on HIBERNATION 181 default "" 182 ---help--- 183 The default resume partition is the partition that the suspend- 184 to-disk implementation will look for a suspended disk image. 185 186 The partition specified here will be different for almost every user. 187 It should be a valid swap partition (at least for now) that is turned 188 on before suspending. 189 190 The partition specified can be overridden by specifying: 191 192 resume=/dev/<other device> 193 194 which will set the resume partition to the device specified. 195 196 Note there is currently not a way to specify which device to save the 197 suspended image to. It will simply pick the first available swap 198 device. 199 200config APM_EMULATION 201 tristate "Advanced Power Management Emulation" 202 depends on PM && SYS_SUPPORTS_APM_EMULATION 203 help 204 APM is a BIOS specification for saving power using several different 205 techniques. This is mostly useful for battery powered laptops with 206 APM compliant BIOSes. If you say Y here, the system time will be 207 reset after a RESUME operation, the /proc/apm device will provide 208 battery status information, and user-space programs will receive 209 notification of APM "events" (e.g. battery status change). 210 211 In order to use APM, you will need supporting software. For location 212 and more information, read <file:Documentation/power/pm.txt> and the 213 Battery Powered Linux mini-HOWTO, available from 214 <http://www.tldp.org/docs.html#howto>. 215 216 This driver does not spin down disk drives (see the hdparm(8) 217 manpage ("man 8 hdparm") for that), and it doesn't turn off 218 VESA-compliant "green" monitors. 219 220 Generally, if you don't have a battery in your machine, there isn't 221 much point in using this driver and you should say N. If you get 222 random kernel OOPSes or reboots that don't seem to be related to 223 anything, try disabling/enabling this option (or disabling/enabling 224 APM in your BIOS). 225 226config PM_RUNTIME 227 bool "Run-time PM core functionality" 228 depends on PM 229 ---help--- 230 Enable functionality allowing I/O devices to be put into energy-saving 231 (low power) states at run time (or autosuspended) after a specified 232 period of inactivity and woken up in response to a hardware-generated 233 wake-up event or a driver's request. 234 235 Hardware support is generally required for this functionality to work 236 and the bus type drivers of the buses the devices are on are 237 responsible for the actual handling of the autosuspend requests and 238 wake-up events. 239 240config PM_OPS 241 bool 242 depends on PM_SLEEP || PM_RUNTIME 243 default y 244