77437fd4e6
Boot-time test for system suspend states (STR or standby). The generic
RTC framework triggers wakeup alarms, which are used to exit those states.
- Measures some aspects of suspend time ... this uses "jiffies" until
someone converts it to use a timebase that works properly even while
timer IRQs are disabled.
- Triggered by a command line parameter. By default nothing even
vaguely troublesome will happen, but "test_suspend=mem" will give
you a brief STR test during system boot. (Or you may need to use
"test_suspend=standby" instead, if your hardware needs that.)
This isn't without problems. It fires early enough during boot that for
example both PCMCIA and MMC stacks have misbehaved. The workaround in
those cases was to boot without such media cards inserted.
[matthltc@us.ibm.com: fix compile failure in boot time suspend selftest]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
206 lines
7.7 KiB
Text
206 lines
7.7 KiB
Text
config PM
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bool "Power Management support"
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depends on !IA64_HP_SIM
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---help---
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"Power Management" means that parts of your computer are shut
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off or put into a power conserving "sleep" mode if they are not
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being used. There are two competing standards for doing this: APM
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and ACPI. If you want to use either one, say Y here and then also
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to the requisite support below.
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Power Management is most important for battery powered laptop
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computers; if you have a laptop, check out the Linux Laptop home
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page on the WWW at <http://www.linux-on-laptops.com/> or
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Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/>
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and the Battery Powered Linux mini-HOWTO, available from
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<http://www.tldp.org/docs.html#howto>.
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Note that, even if you say N here, Linux on the x86 architecture
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will issue the hlt instruction if nothing is to be done, thereby
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sending the processor to sleep and saving power.
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config PM_DEBUG
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bool "Power Management Debug Support"
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depends on PM
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---help---
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This option enables various debugging support in the Power Management
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code. This is helpful when debugging and reporting PM bugs, like
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suspend support.
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config PM_VERBOSE
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bool "Verbose Power Management debugging"
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depends on PM_DEBUG
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default n
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---help---
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This option enables verbose messages from the Power Management code.
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config CAN_PM_TRACE
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def_bool y
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depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL
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config PM_TRACE
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bool
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help
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This enables code to save the last PM event point across
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reboot. The architecture needs to support this, x86 for
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example does by saving things in the RTC, see below.
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The architecture specific code must provide the extern
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functions from <linux/resume-trace.h> as well as the
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<asm/resume-trace.h> header with a TRACE_RESUME() macro.
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The way the information is presented is architecture-
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dependent, x86 will print the information during a
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late_initcall.
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config PM_TRACE_RTC
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bool "Suspend/resume event tracing"
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depends on CAN_PM_TRACE
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depends on X86
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select PM_TRACE
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default n
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---help---
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This enables some cheesy code to save the last PM event point in the
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RTC across reboots, so that you can debug a machine that just hangs
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during suspend (or more commonly, during resume).
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To use this debugging feature you should attempt to suspend the
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machine, reboot it and then run
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dmesg -s 1000000 | grep 'hash matches'
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CAUTION: this option will cause your machine's real-time clock to be
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set to an invalid time after a resume.
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config PM_SLEEP_SMP
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bool
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depends on SMP
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depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
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depends on PM_SLEEP
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select HOTPLUG_CPU
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default y
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config PM_SLEEP
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bool
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depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
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default y
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config SUSPEND
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bool "Suspend to RAM and standby"
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depends on PM && ARCH_SUSPEND_POSSIBLE
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default y
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---help---
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Allow the system to enter sleep states in which main memory is
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powered and thus its contents are preserved, such as the
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suspend-to-RAM state (e.g. the ACPI S3 state).
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config PM_TEST_SUSPEND
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bool "Test suspend/resume and wakealarm during bootup"
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depends on SUSPEND && PM_DEBUG && RTC_LIB=y
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---help---
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This option will let you suspend your machine during bootup, and
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make it wake up a few seconds later using an RTC wakeup alarm.
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Enable this with a kernel parameter like "test_suspend=mem".
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You probably want to have your system's RTC driver statically
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linked, ensuring that it's available when this test runs.
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config SUSPEND_FREEZER
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bool "Enable freezer for suspend to RAM/standby" \
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if ARCH_WANTS_FREEZER_CONTROL || BROKEN
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depends on SUSPEND
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default y
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help
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This allows you to turn off the freezer for suspend. If this is
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done, no tasks are frozen for suspend to RAM/standby.
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Turning OFF this setting is NOT recommended! If in doubt, say Y.
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config HIBERNATION
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bool "Hibernation (aka 'suspend to disk')"
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depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
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---help---
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Enable the suspend to disk (STD) functionality, which is usually
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called "hibernation" in user interfaces. STD checkpoints the
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system and powers it off; and restores that checkpoint on reboot.
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You can suspend your machine with 'echo disk > /sys/power/state'
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after placing resume=/dev/swappartition on the kernel command line
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in your bootloader's configuration file.
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Alternatively, you can use the additional userland tools available
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from <http://suspend.sf.net>.
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In principle it does not require ACPI or APM, although for example
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ACPI will be used for the final steps when it is available. One
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of the reasons to use software suspend is that the firmware hooks
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for suspend states like suspend-to-RAM (STR) often don't work very
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well with Linux.
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It creates an image which is saved in your active swap. Upon the next
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boot, pass the 'resume=/dev/swappartition' argument to the kernel to
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have it detect the saved image, restore memory state from it, and
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continue to run as before. If you do not want the previous state to
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be reloaded, then use the 'noresume' kernel command line argument.
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Note, however, that fsck will be run on your filesystems and you will
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need to run mkswap against the swap partition used for the suspend.
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It also works with swap files to a limited extent (for details see
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<file:Documentation/power/swsusp-and-swap-files.txt>).
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Right now you may boot without resuming and resume later but in the
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meantime you cannot use the swap partition(s)/file(s) involved in
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suspending. Also in this case you must not use the filesystems
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that were mounted before the suspend. In particular, you MUST NOT
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MOUNT any journaled filesystems mounted before the suspend or they
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will get corrupted in a nasty way.
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For more information take a look at <file:Documentation/power/swsusp.txt>.
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config PM_STD_PARTITION
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string "Default resume partition"
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depends on HIBERNATION
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default ""
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---help---
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The default resume partition is the partition that the suspend-
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to-disk implementation will look for a suspended disk image.
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The partition specified here will be different for almost every user.
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It should be a valid swap partition (at least for now) that is turned
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on before suspending.
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The partition specified can be overridden by specifying:
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resume=/dev/<other device>
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which will set the resume partition to the device specified.
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Note there is currently not a way to specify which device to save the
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suspended image to. It will simply pick the first available swap
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device.
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config APM_EMULATION
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tristate "Advanced Power Management Emulation"
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depends on PM && SYS_SUPPORTS_APM_EMULATION
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help
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APM is a BIOS specification for saving power using several different
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techniques. This is mostly useful for battery powered laptops with
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APM compliant BIOSes. If you say Y here, the system time will be
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reset after a RESUME operation, the /proc/apm device will provide
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battery status information, and user-space programs will receive
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notification of APM "events" (e.g. battery status change).
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In order to use APM, you will need supporting software. For location
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and more information, read <file:Documentation/power/pm.txt> and the
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Battery Powered Linux mini-HOWTO, available from
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<http://www.tldp.org/docs.html#howto>.
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This driver does not spin down disk drives (see the hdparm(8)
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manpage ("man 8 hdparm") for that), and it doesn't turn off
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VESA-compliant "green" monitors.
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Generally, if you don't have a battery in your machine, there isn't
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much point in using this driver and you should say N. If you get
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random kernel OOPSes or reboots that don't seem to be related to
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anything, try disabling/enabling this option (or disabling/enabling
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APM in your BIOS).
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