![Andres Salomon](/assets/img/avatar_default.png)
Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop the serial console from being suspended when the rest of the machine goes to sleep. This is incredibly useful for debugging power management-related things; however, having it as a compile-time option has proved to be incredibly inconvenient for us (OLPC). There are plenty of times that we want serial console to not suspend, but for the most part we'd like serial console to be suspended. This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel boot parameter (no_console_suspend). By default, the serial console will be suspended along with the rest of the system; by passing 'no_console_suspend' to the kernel during boot, serial console will remain alive during suspend. For now, this is pretty serial console specific; further fixes could be applied to make this work for things like netconsole. Signed-off-by: Andres Salomon <dilinger@debian.org> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@suspend2.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
198 lines
6.9 KiB
Text
198 lines
6.9 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_LEGACY
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bool "Legacy Power Management API (DEPRECATED)"
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depends on PM
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default n
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---help---
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Support for pm_register() and friends. This old API is obsoleted
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by the driver model.
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If unsure, say N.
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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 PM_TRACE
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bool "Suspend/resume event tracing"
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depends on PM_DEBUG && X86 && PM_SLEEP && EXPERIMENTAL
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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 machine,
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then reboot it, 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 SUSPEND_SMP_POSSIBLE || HIBERNATION_SMP_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
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default y
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config SUSPEND_UP_POSSIBLE
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bool
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depends on (X86 && !X86_VOYAGER) || PPC || ARM || BLACKFIN || MIPS \
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|| SUPERH || FRV
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depends on !SMP
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default y
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config SUSPEND_SMP_POSSIBLE
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bool
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depends on (X86 && !X86_VOYAGER) \
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|| (PPC && (PPC_PSERIES || PPC_PMAC)) || ARM
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depends on SMP
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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
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depends on SUSPEND_UP_POSSIBLE || SUSPEND_SMP_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 (i.e. the ACPI S3 state).
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config HIBERNATION_UP_POSSIBLE
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bool
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depends on X86 || PPC64_SWSUSP || PPC32
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depends on !SMP
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default y
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config HIBERNATION_SMP_POSSIBLE
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bool
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depends on (X86 && !X86_VOYAGER) || PPC64_SWSUSP
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depends on SMP
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default 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
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depends on HIBERNATION_UP_POSSIBLE || HIBERNATION_SMP_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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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/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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