| config PM |
| bool "Power Management support" |
| depends on !IA64_HP_SIM |
| ---help--- |
| "Power Management" means that parts of your computer are shut |
| off or put into a power conserving "sleep" mode if they are not |
| being used. There are two competing standards for doing this: APM |
| and ACPI. If you want to use either one, say Y here and then also |
| to the requisite support below. |
| |
| Power Management is most important for battery powered laptop |
| computers; if you have a laptop, check out the Linux Laptop home |
| page on the WWW at <http://www.linux-on-laptops.com/> or |
| Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/> |
| and the Battery Powered Linux mini-HOWTO, available from |
| <http://www.tldp.org/docs.html#howto>. |
| |
| Note that, even if you say N here, Linux on the x86 architecture |
| will issue the hlt instruction if nothing is to be done, thereby |
| sending the processor to sleep and saving power. |
| |
| config PM_DEBUG |
| bool "Power Management Debug Support" |
| depends on PM |
| ---help--- |
| This option enables various debugging support in the Power Management |
| code. This is helpful when debugging and reporting PM bugs, like |
| suspend support. |
| |
| config PM_VERBOSE |
| bool "Verbose Power Management debugging" |
| depends on PM_DEBUG |
| default n |
| ---help--- |
| This option enables verbose messages from the Power Management code. |
| |
| config CAN_PM_TRACE |
| def_bool y |
| depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL |
| |
| config PM_TRACE |
| bool |
| help |
| This enables code to save the last PM event point across |
| reboot. The architecture needs to support this, x86 for |
| example does by saving things in the RTC, see below. |
| |
| The architecture specific code must provide the extern |
| functions from <linux/resume-trace.h> as well as the |
| <asm/resume-trace.h> header with a TRACE_RESUME() macro. |
| |
| The way the information is presented is architecture- |
| dependent, x86 will print the information during a |
| late_initcall. |
| |
| config PM_TRACE_RTC |
| bool "Suspend/resume event tracing" |
| depends on CAN_PM_TRACE |
| depends on X86 |
| select PM_TRACE |
| default n |
| ---help--- |
| This enables some cheesy code to save the last PM event point in the |
| RTC across reboots, so that you can debug a machine that just hangs |
| during suspend (or more commonly, during resume). |
| |
| To use this debugging feature you should attempt to suspend the |
| machine, reboot it and then run |
| |
| dmesg -s 1000000 | grep 'hash matches' |
| |
| CAUTION: this option will cause your machine's real-time clock to be |
| set to an invalid time after a resume. |
| |
| config PM_SLEEP_SMP |
| bool |
| depends on SMP |
| depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE |
| depends on PM_SLEEP |
| select HOTPLUG_CPU |
| default y |
| |
| config PM_SLEEP |
| bool |
| depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE |
| default y |
| |
| config SUSPEND |
| bool "Suspend to RAM and standby" |
| depends on PM && ARCH_SUSPEND_POSSIBLE |
| default y |
| ---help--- |
| Allow the system to enter sleep states in which main memory is |
| powered and thus its contents are preserved, such as the |
| suspend-to-RAM state (e.g. the ACPI S3 state). |
| |
| config PM_TEST_SUSPEND |
| bool "Test suspend/resume and wakealarm during bootup" |
| depends on SUSPEND && PM_DEBUG && RTC_CLASS=y |
| ---help--- |
| This option will let you suspend your machine during bootup, and |
| make it wake up a few seconds later using an RTC wakeup alarm. |
| Enable this with a kernel parameter like "test_suspend=mem". |
| |
| You probably want to have your system's RTC driver statically |
| linked, ensuring that it's available when this test runs. |
| |
| config SUSPEND_FREEZER |
| bool "Enable freezer for suspend to RAM/standby" \ |
| if ARCH_WANTS_FREEZER_CONTROL || BROKEN |
| depends on SUSPEND |
| default y |
| help |
| This allows you to turn off the freezer for suspend. If this is |
| done, no tasks are frozen for suspend to RAM/standby. |
| |
| Turning OFF this setting is NOT recommended! If in doubt, say Y. |
| |
| config HIBERNATION_NVS |
| bool |
| |
| config HIBERNATION |
| bool "Hibernation (aka 'suspend to disk')" |
| depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE |
| select HIBERNATION_NVS if HAS_IOMEM |
| ---help--- |
| Enable the suspend to disk (STD) functionality, which is usually |
| called "hibernation" in user interfaces. STD checkpoints the |
| system and powers it off; and restores that checkpoint on reboot. |
| |
| You can suspend your machine with 'echo disk > /sys/power/state' |
| after placing resume=/dev/swappartition on the kernel command line |
| in your bootloader's configuration file. |
| |
| Alternatively, you can use the additional userland tools available |
| from <http://suspend.sf.net>. |
| |
| In principle it does not require ACPI or APM, although for example |
| ACPI will be used for the final steps when it is available. One |
| of the reasons to use software suspend is that the firmware hooks |
| for suspend states like suspend-to-RAM (STR) often don't work very |
| well with Linux. |
| |
| It creates an image which is saved in your active swap. Upon the next |
| boot, pass the 'resume=/dev/swappartition' argument to the kernel to |
| have it detect the saved image, restore memory state from it, and |
| continue to run as before. If you do not want the previous state to |
| be reloaded, then use the 'noresume' kernel command line argument. |
| Note, however, that fsck will be run on your filesystems and you will |
| need to run mkswap against the swap partition used for the suspend. |
| |
| It also works with swap files to a limited extent (for details see |
| <file:Documentation/power/swsusp-and-swap-files.txt>). |
| |
| Right now you may boot without resuming and resume later but in the |
| meantime you cannot use the swap partition(s)/file(s) involved in |
| suspending. Also in this case you must not use the filesystems |
| that were mounted before the suspend. In particular, you MUST NOT |
| MOUNT any journaled filesystems mounted before the suspend or they |
| will get corrupted in a nasty way. |
| |
| For more information take a look at <file:Documentation/power/swsusp.txt>. |
| |
| config PM_STD_PARTITION |
| string "Default resume partition" |
| depends on HIBERNATION |
| default "" |
| ---help--- |
| The default resume partition is the partition that the suspend- |
| to-disk implementation will look for a suspended disk image. |
| |
| The partition specified here will be different for almost every user. |
| It should be a valid swap partition (at least for now) that is turned |
| on before suspending. |
| |
| The partition specified can be overridden by specifying: |
| |
| resume=/dev/<other device> |
| |
| which will set the resume partition to the device specified. |
| |
| Note there is currently not a way to specify which device to save the |
| suspended image to. It will simply pick the first available swap |
| device. |
| |
| config APM_EMULATION |
| tristate "Advanced Power Management Emulation" |
| depends on PM && SYS_SUPPORTS_APM_EMULATION |
| help |
| APM is a BIOS specification for saving power using several different |
| techniques. This is mostly useful for battery powered laptops with |
| APM compliant BIOSes. If you say Y here, the system time will be |
| reset after a RESUME operation, the /proc/apm device will provide |
| battery status information, and user-space programs will receive |
| notification of APM "events" (e.g. battery status change). |
| |
| In order to use APM, you will need supporting software. For location |
| and more information, read <file:Documentation/power/pm.txt> and the |
| Battery Powered Linux mini-HOWTO, available from |
| <http://www.tldp.org/docs.html#howto>. |
| |
| This driver does not spin down disk drives (see the hdparm(8) |
| manpage ("man 8 hdparm") for that), and it doesn't turn off |
| VESA-compliant "green" monitors. |
| |
| Generally, if you don't have a battery in your machine, there isn't |
| much point in using this driver and you should say N. If you get |
| random kernel OOPSes or reboots that don't seem to be related to |
| anything, try disabling/enabling this option (or disabling/enabling |
| APM in your BIOS). |
| |
| config PM_RUNTIME |
| bool "Run-time PM core functionality" |
| depends on PM |
| ---help--- |
| Enable functionality allowing I/O devices to be put into energy-saving |
| (low power) states at run time (or autosuspended) after a specified |
| period of inactivity and woken up in response to a hardware-generated |
| wake-up event or a driver's request. |
| |
| Hardware support is generally required for this functionality to work |
| and the bus type drivers of the buses the devices are on are |
| responsible for the actual handling of the autosuspend requests and |
| wake-up events. |
