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+# SPDX-License-Identifier: GPL-2.0-only
+config SUSPEND
+ bool "Suspend to RAM and standby"
+ depends on 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 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 SUSPEND_SKIP_SYNC
+ bool "Skip kernel's sys_sync() on suspend to RAM/standby"
+ depends on SUSPEND
+ depends on EXPERT
+ help
+ Skip the kernel sys_sync() before freezing user processes.
+ Some systems prefer not to pay this cost on every invocation
+ of suspend, or they are content with invoking sync() from
+ user-space before invoking suspend. There's a run-time switch
+ at '/sys/power/sync_on_suspend' to configure this behaviour.
+ This setting changes the default for the run-tim switch. Say Y
+ to change the default to disable the kernel sys_sync().
+
+config HIBERNATE_CALLBACKS
+ bool
+
+config HIBERNATION
+ bool "Hibernation (aka 'suspend to disk')"
+ depends on SWAP && ARCH_HIBERNATION_POSSIBLE
+ select HIBERNATE_CALLBACKS
+ select LZO_COMPRESS
+ select LZO_DECOMPRESS
+ select CRC32
+ 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.rst>).
+
+ 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.rst>.
+
+config HIBERNATION_SNAPSHOT_DEV
+ bool "Userspace snapshot device"
+ depends on HIBERNATION
+ default y
+ help
+ Device used by the uswsusp tools.
+
+ Say N if no snapshotting from userspace is needed, this also
+ reduces the attack surface of the kernel.
+
+ If in doubt, say Y.
+
+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 PM_SLEEP
+ def_bool y
+ depends on SUSPEND || HIBERNATE_CALLBACKS
+ select PM
+
+config PM_SLEEP_SMP
+ def_bool y
+ depends on SMP
+ depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
+ depends on PM_SLEEP
+ select HOTPLUG_CPU
+
+config PM_SLEEP_SMP_NONZERO_CPU
+ def_bool y
+ depends on PM_SLEEP_SMP
+ depends on ARCH_SUSPEND_NONZERO_CPU
+ help
+ If an arch can suspend (for suspend, hibernate, kexec, etc) on a
+ non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This
+ will allow nohz_full mask to include CPU0.
+
+config PM_AUTOSLEEP
+ bool "Opportunistic sleep"
+ depends on PM_SLEEP
+ help
+ Allow the kernel to trigger a system transition into a global sleep
+ state automatically whenever there are no active wakeup sources.
+
+config PM_USERSPACE_AUTOSLEEP
+ bool "Userspace opportunistic sleep"
+ depends on PM_SLEEP
+ help
+ Notify kernel of aggressive userspace autosleep power management policy.
+
+ This option changes the behavior of various sleep-sensitive code to deal
+ with frequent userspace-initiated transitions into a global sleep state.
+
+ Saying Y here, disables code paths that most users really should keep
+ enabled. In particular, only enable this if it is very common to be
+ asleep/awake for very short periods of time (<= 2 seconds).
+
+ Only platforms, such as Android, that implement opportunistic sleep from
+ a userspace power manager service should enable this option; and not
+ other machines. Therefore, you should say N here, unless you are
+ extremely certain that this is what you want. The option otherwise has
+ bad, undesirable effects, and should not be enabled just for fun.
+
+
+config PM_WAKELOCKS
+ bool "User space wakeup sources interface"
+ depends on PM_SLEEP
+ help
+ Allow user space to create, activate and deactivate wakeup source
+ objects with the help of a sysfs-based interface.
+
+config PM_WAKELOCKS_LIMIT
+ int "Maximum number of user space wakeup sources (0 = no limit)"
+ range 0 100000
+ default 100
+ depends on PM_WAKELOCKS
+
+config PM_WAKELOCKS_GC
+ bool "Garbage collector for user space wakeup sources"
+ depends on PM_WAKELOCKS
+ default y
+
+config PM
+ bool "Device power management core functionality"
+ help
+ Enable functionality allowing I/O devices to be put into energy-saving
+ (low power) states, for example after a specified period of inactivity
+ (autosuspended), 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 device suspend requests and
+ wake-up events.
+
+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_ADVANCED_DEBUG
+ bool "Extra PM attributes in sysfs for low-level debugging/testing"
+ depends on PM_DEBUG
+ help
+ Add extra sysfs attributes allowing one to access some Power Management
+ fields of device objects from user space. If you are not a kernel
+ developer interested in debugging/testing Power Management, say "no".
+
+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 PM_SLEEP_DEBUG
+ def_bool y
+ depends on PM_DEBUG && PM_SLEEP
+
+config DPM_WATCHDOG
+ bool "Device suspend/resume watchdog"
+ depends on PM_DEBUG && PSTORE && EXPERT
+ help
+ Sets up a watchdog timer to capture drivers that are
+ locked up attempting to suspend/resume a device.
+ A detected lockup causes system panic with message
+ captured in pstore device for inspection in subsequent
+ boot session.
+
+config DPM_WATCHDOG_TIMEOUT
+ int "Watchdog timeout in seconds"
+ range 1 120
+ default 120
+ depends on DPM_WATCHDOG
+
+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 PM_SLEEP_DEBUG
+ depends on X86
+ select PM_TRACE
+ 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 APM_EMULATION
+ tristate "Advanced Power Management Emulation"
+ depends on 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/apm-acpi.rst>
+ 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_CLK
+ def_bool y
+ depends on PM && HAVE_CLK
+
+config PM_GENERIC_DOMAINS
+ bool
+ depends on PM
+
+config WQ_POWER_EFFICIENT_DEFAULT
+ bool "Enable workqueue power-efficient mode by default"
+ depends on PM
+ help
+ Per-cpu workqueues are generally preferred because they show
+ better performance thanks to cache locality; unfortunately,
+ per-cpu workqueues tend to be more power hungry than unbound
+ workqueues.
+
+ Enabling workqueue.power_efficient kernel parameter makes the
+ per-cpu workqueues which were observed to contribute
+ significantly to power consumption unbound, leading to measurably
+ lower power usage at the cost of small performance overhead.
+
+ This config option determines whether workqueue.power_efficient
+ is enabled by default.
+
+ If in doubt, say N.
+
+config PM_GENERIC_DOMAINS_SLEEP
+ def_bool y
+ depends on PM_SLEEP && PM_GENERIC_DOMAINS
+
+config PM_GENERIC_DOMAINS_OF
+ def_bool y
+ depends on PM_GENERIC_DOMAINS && OF
+
+config CPU_PM
+ bool
+
+config ENERGY_MODEL
+ bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)"
+ depends on SMP
+ depends on CPU_FREQ
+ help
+ Several subsystems (thermal and/or the task scheduler for example)
+ can leverage information about the energy consumed by devices to
+ make smarter decisions. This config option enables the framework
+ from which subsystems can access the energy models.
+
+ The exact usage of the energy model is subsystem-dependent.
+
+ If in doubt, say N.