| # 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 CRC32 | |
| select CRYPTO | |
| select CRYPTO_LZO | |
| select CRYPTO_LZ4 | |
| 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. | |
| choice | |
| prompt "Default compressor" | |
| default HIBERNATION_COMP_LZO | |
| depends on HIBERNATION | |
| config HIBERNATION_COMP_LZO | |
| bool "lzo" | |
| depends on CRYPTO_LZO | |
| config HIBERNATION_COMP_LZ4 | |
| bool "lz4" | |
| depends on CRYPTO_LZ4 | |
| endchoice | |
| config HIBERNATION_DEF_COMP | |
| string | |
| default "lzo" if HIBERNATION_COMP_LZO | |
| default "lz4" if HIBERNATION_COMP_LZ4 | |
| help | |
| Default compressor to be used for hibernation. | |
| 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_QOS_CPU_SYSTEM_WAKEUP | |
| bool "User space interface for CPU system wakeup QoS" | |
| depends on CPU_IDLE | |
| help | |
| Enable this to allow user space via the cpu_wakeup_latency file to | |
| specify a CPU system wakeup latency limit. | |
| This may be particularly useful for platforms supporting multiple low | |
| power states for CPUs during system-wide suspend and s2idle in | |
| particular. | |
| 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_ENABLED | |
| bool "Enable DPM watchdog by default" | |
| depends on DPM_WATCHDOG | |
| default y | |
| help | |
| If you say Y here, the DPM watchdog will be enabled by default. | |
| If you say N, it will be compiled in but disabled. It can be | |
| enabled at boot time via the "pm.dpm_watchdog_enabled" kernel | |
| parameter or at runtime via sysfs. | |
| config DPM_WATCHDOG_TIMEOUT | |
| int "Watchdog timeout to panic in seconds" | |
| range 1 120 | |
| default 120 | |
| depends on DPM_WATCHDOG | |
| config DPM_WATCHDOG_WARNING_TIMEOUT | |
| int "Watchdog timeout to warn in seconds" | |
| range 1 DPM_WATCHDOG_TIMEOUT | |
| default DPM_WATCHDOG_TIMEOUT | |
| depends on DPM_WATCHDOG | |
| help | |
| If the DPM watchdog warning timeout and main timeout are | |
| different then a non-fatal warning (with a stack trace of | |
| the stuck suspend routine) will be printed when the warning | |
| timeout expires. If the suspend routine gets un-stuck | |
| before the main timeout expires then no other action is | |
| taken. If the routine continues to be stuck and the main | |
| timeout expires then an emergency-level message and stack | |
| trace will be printed and the system will panic. | |
| If the warning timeout is equal to the main timeout (the | |
| default) then the warning will never happen and the system | |
| will jump straight to panic when the main timeout expires. | |
| 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 CPU_FREQ || PM_DEVFREQ | |
| 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. |