| # 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. |
