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2022-09-27Documentation/ABI: correct possessive "its" typosRandy Dunlap1-1/+1
Correct all uses of "it's" that are meant to be possessive "its". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220801025207.29971-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-08-13platform/x86: Update Mario Limonciello's email address in the docsHans de Goede1-1/+1
Various pdx86 docs under Documentation/ABI/testing still use Mario's old, now defunct, <mario.limonciello@dell.com> address. Update the docs to point to either the new Dell.Client.Kernel@dell.com email alias for Dell specific drivers, or to Mario's new @outlook.com address for other drivers. Cc: Dell.Client.Kernel@dell.com Cc: Mario Limonciello <mario.limonciello@outlook.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20210810160900.106512-1-hdegoede@redhat.com
2020-10-30docs: ABI: cleanup several ABI documentsMauro Carvalho Chehab1-8/+13
There are some ABI documents that, while they don't generate any warnings, they have issues when parsed by get_abi.pl script on its output result. Address them, in order to provide a clean output. Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7 Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-16PM: suspend: Add sysfs attribute to control the "sync on suspend" behaviorJonas Meurer1-0/+13
The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not filesystems are synced by the kernel before system suspend. Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC is slightly changed: It now defines the run-tim default for the new sysfs attribute `/sys/power/sync_on_suspend`. The run-time attribute is added because the existing corresponding build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible enough. E.g. Linux distributions that provide pre-compiled kernels usually want to stick with the default (sync filesystems before suspend) but under special conditions this needs to be changed. One example for such a special condition is user-space handling of suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup suspend`) before system suspend. The Kernel trying to sync filesystems after the underlying block device already got suspended obviously leads to dead-locks. Be aware that you have to take care of the filesystem sync yourself before suspending the system in those scenarios. Signed-off-by: Jonas Meurer <jonas@freesources.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-05PM/sleep: Expose suspend stats in sysfsKalesh Singh1-0/+106
Userspace can get suspend stats from the suspend stats debugfs node. Since debugfs doesn't have stable ABI, expose suspend stats in sysfs under /sys/power/suspend_stats. Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-03Documentation: ABI: power: Add missing newline at end of fileGeert Uytterhoeven1-1/+1
"git diff" says: \ No newline at end of file after modifying the files. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-09-10PM / hibernate: Documentation: fix image_size default valueVladimir D. Seleznev1-1/+1
This commit updates the default value of /sys/power/image_size in the documentation. Since ac5c24ec1e983313ef0015258fba6f630e54e7cn the `image_size' value is set to about 2/5 of RAM, according to kernel/power/snapshot.c: image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; but this change was not reflected everywhere in the documentation. Signed-off-by: Vladimir D. Seleznev <vseleznv@altlinux.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-03-30PM / hibernate: Make passing hibernate offsets more friendlyMario Limonciello1-0/+14
Currently the only way to specify a hibernate offset for a swap file is on the kernel command line. Add a new /sys/power/resume_offset that lets userspace specify the offset and disk to use when initiating a hibernate cycle. Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-13Merge tag 'docs-4.15' of git://git.lwn.net/linuxLinus Torvalds1-2/+4
Pull documentation updates from Jonathan Corbet: "A relatively calm cycle for the docs tree again. - The old driver statement has been added to the kernel docs. - We have a couple of new helper scripts. find-unused-docs.sh from Sayli Karnic will point out kerneldoc comments that are not actually used in the documentation. Jani Nikula's documentation-file-ref-check finds references to non-existing files. - A new ftrace document from Steve Rostedt. - Vinod Koul converted the dmaengine docs to RST Beyond that, it's mostly simple fixes. This set reaches outside of Documentation/ a bit more than most. In all cases, the changes are to comment docs, mostly from Randy, in places where there didn't seem to be anybody better to take them" * tag 'docs-4.15' of git://git.lwn.net/linux: (52 commits) documentation: fb: update list of available compiled-in fonts MAINTAINERS: update DMAengine documentation location dmaengine: doc: ReSTize pxa_dma doc dmaengine: doc: ReSTize dmatest doc dmaengine: doc: ReSTize client API doc dmaengine: doc: ReSTize provider doc dmaengine: doc: Add ReST style dmaengine document ftrace/docs: Add documentation on how to use ftrace from within the kernel bug-hunting.rst: Fix an example and a typo in a Sphinx tag scripts: Add a script to find unused documentation samples: Convert timers to use timer_setup() documentation: kernel-api: add more info on bitmap functions Documentation: fix selftests related file refs Documentation: fix ref to power basic-pm-debugging Documentation: fix ref to trace stm content Documentation: fix ref to coccinelle content Documentation: fix ref to workqueue content Documentation: fix ref to sphinx/kerneldoc.py Documentation: fix locking rt-mutex doc refs docs: dev-tools: correct Coccinelle version number ...
2017-10-12Documentation: fix admin-guide doc refsTom Saeger1-2/+4
Make admin-guide document refs valid. Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-10-04Update James Hogan's email addressJames Hogan1-1/+1
Update my imgtec.com and personal email address to my kernel.org one in a few places as MIPS will soon no longer be part of Imagination Technologies, and add mappings in .mailcap so get_maintainer.pl reports the right address. Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-22PM / sleep: Do not print debug messages by defaultRafael J. Wysocki1-0/+12
Debug messages from the system suspend/hibernation infrastructure can fill up the entire kernel log buffer in some cases and anyway they are only useful for debugging. They depend on CONFIG_PM_DEBUG, but that is set as a rule as some generally useful diagnostic facilities depend on it too. For this reason, avoid printing those messages by default, but make it possible to turn them on as needed with the help of a new sysfs attribute under /sys/power/. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-21PM / sleep: System sleep state selection interface reworkRafael J. Wysocki1-20/+25
There are systems in which the platform doesn't support any special sleep states, so suspend-to-idle (PM_SUSPEND_FREEZE) is the only available system sleep state. However, some user space frameworks only use the "mem" and (sometimes) "standby" sleep state labels, so the users of those systems need to modify user space in order to be able to use system suspend at all and that may be a pain in practice. Commit 0399d4db3edf (PM / sleep: Introduce command line argument for sleep state enumeration) attempted to address this problem by adding a command line argument to change the meaning of the "mem" string in /sys/power/state to make it trigger suspend-to-idle (instead of suspend-to-RAM). However, there also are systems in which the platform does support special sleep states, but suspend-to-idle is the preferred one anyway (it even may save more energy than the platform-provided sleep states in some cases) and the above commit doesn't help in those cases. For this reason, rework the system sleep state selection interface again (but preserve backwards compatibiliby). Namely, add a new sysfs file, /sys/power/mem_sleep, that will control the system suspend mode triggered by writing "mem" to /sys/power/state (in analogy with what /sys/power/disk does for hibernation). Make it select suspend-to-RAM ("deep" sleep) by default (if supported) and fall back to suspend-to-idle ("s2idle") otherwise and add a new command line argument, mem_sleep_default, allowing that default to be overridden if need be. At the same time, drop the relative_sleep_states command line argument that doesn't make sense any more. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mario Limonciello <mario.limonciello@dell.com>
2015-09-16PM / sleep: Report interrupt that caused system wakeupAlexandra Yates1-0/+12
Add a sysfs attribute, /sys/power/pm_wakeup_irq, reporting the IRQ number of the first wakeup interrupt (that is, the first interrupt from an IRQ line armed for system wakeup) seen by the kernel during the most recent system suspend/resume cycle. This feature will be useful for system wakeup diagnostics of spurious wakeup interrupts. Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com> [ rjw: Fixed up pm_wakeup_irq definition ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-26PM / sleep: Introduce command line argument for sleep state enumerationRafael J. Wysocki1-9/+20
On some systems the platform doesn't support neither PM_SUSPEND_MEM nor PM_SUSPEND_STANDBY, so PM_SUSPEND_FREEZE is the only available system sleep state. However, some user space frameworks only use the "mem" and (sometimes) "standby" sleep state labels, so the users of those systems need to modify user space in order to be able to use system suspend at all and that is not always possible. For this reason, add a new kernel command line argument, relative_sleep_states, allowing the users of those systems to change the way in which the kernel assigns labels to system sleep states. Namely, for relative_sleep_states=1, the "mem", "standby" and "freeze" labels will enumerate the available system sleem states from the deepest to the shallowest, respectively, so that "mem" is always present in /sys/power/state and the other state strings may or may not be presend depending on what is supported by the platform. Update system sleep states documentation to reflect this change. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-12PM: Add missing "freeze" stateGeert Uytterhoeven1-2/+3
Fix descriptions of /sys/power/state in the documentation and in a code comment. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Pavel Machek <pavel@ucw.cz> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-09MAINTAINERS / Documentation: Update Rafael's e-mail addressRafael J. Wysocki1-11/+11
The e-mail address rjw@sisk.pl that I have been using for quite some time is going to expire at one point, so replace it with a new one, rjw@rjwysocki.net, everywhere in MAINTAINERS and Documentation/ABI. Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2012-07-01PM / Sleep: add knob for printing device resume timesSameer Nanda1-0/+13
Added a new knob called /sys/power/pm_print_times. Setting it to 1 enables printing of time taken by devices to suspend and resume. Setting it to 0 disables this printing (unless overridden by initcall_debug kernel command line option). Signed-off-by: Sameer Nanda <snanda@chromium.org> Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-01PM / Sleep: Add user space interface for manipulating wakeup sources, v3Rafael J. Wysocki1-0/+42
Android allows user space to manipulate wakelocks using two sysfs file located in /sys/power/, wake_lock and wake_unlock. Writing a wakelock name and optionally a timeout to the wake_lock file causes the wakelock whose name was written to be acquired (it is created before is necessary), optionally with the given timeout. Writing the name of a wakelock to wake_unlock causes that wakelock to be released. Implement an analogous interface for user space using wakeup sources. Add the /sys/power/wake_lock and /sys/power/wake_unlock files allowing user space to create, activate and deactivate wakeup sources, such that writing a name and optionally a timeout to wake_lock causes the wakeup source of that name to be activated, optionally with the given timeout. If that wakeup source doesn't exist, it will be created and then activated. Writing a name to wake_unlock causes the wakeup source of that name, if there is one, to be deactivated. Wakeup sources created with the help of wake_lock that haven't been used for more than 5 minutes are garbage collected and destroyed. Moreover, there can be only WL_NUMBER_LIMIT wakeup sources created with the help of wake_lock present at a time. The data type used to track wakeup sources created by user space is called "struct wakelock" to indicate the origins of this feature. This version of the patch includes an rbtree manipulation fix from John Stultz. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NeilBrown <neilb@suse.de>
2012-05-01PM / Sleep: Implement opportunistic sleep, v2Rafael J. Wysocki1-0/+17
Introduce a mechanism by which the kernel can trigger global transitions to a sleep state chosen by user space if there are no active wakeup sources. It consists of a new sysfs attribute, /sys/power/autosleep, that can be written one of the strings returned by reads from /sys/power/state, an ordered workqueue and a work item carrying out the "suspend" operations. If a string representing the system's sleep state is written to /sys/power/autosleep, the work item triggering transitions to that state is queued up and it requeues itself after every execution until user space writes "off" to /sys/power/autosleep. That work item enables the detection of wakeup events using the functions already defined in drivers/base/power/wakeup.c (with one small modification) and calls either pm_suspend(), or hibernate() to put the system into a sleep state. If a wakeup event is reported while the transition is in progress, it will abort the transition and the "system suspend" work item will be queued up again. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NeilBrown <neilb@suse.de>
2011-05-17PM / Hibernate: Add sysfs knob to control size of memory for driversRafael J. Wysocki1-0/+14
Martin reports that on his system hibernation occasionally fails due to the lack of memory, because the radeon driver apparently allocates too much of it during the device freeze stage. It turns out that the amount of memory allocated by radeon during hibernation (and presumably during system suspend too) depends on the utilization of the GPU (e.g. hibernating while there are two KDE 4 sessions with compositing enabled causes radeon to allocate more memory than for one KDE 4 session). In principle it should be possible to use image_size to make the memory preallocation mechanism free enough memory for the radeon driver, but in practice it is not easy to guess the right value because of the way the preallocation code uses image_size. For this reason, it seems reasonable to allow users to control the amount of memory reserved for driver allocations made after the hibernate preallocation, which currently is constant and amounts to 1 MB. Introduce a new sysfs file, /sys/power/reserved_size, whose value will be used as the amount of memory to reserve for the post-preallocation reservations made by device drivers, in bytes. For backwards compatibility, set its default (and initial) value to the currently used number (1 MB). References: https://bugzilla.kernel.org/show_bug.cgi?id=34102 Reported-and-tested-by: Martin Steigerwald <Martin@Lichtvoll.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM: Add sysfs attr for rechecking dev hash from PM traceJames Hogan1-0/+29
If the device which fails to resume is part of a loadable kernel module it won't be checked at startup against the magic number stored in the RTC. Add a read-only sysfs attribute /sys/power/pm_trace_dev_match which contains a list of newline separated devices (usually just the one) which currently match the last magic number. This allows the device which is failing to resume to be found after the modules are loaded again. Signed-off-by: James Hogan <james@albanarts.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-19PM: Make it possible to avoid races between wakeup and system sleepRafael J. Wysocki1-0/+15
One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-02-26PM: Add a switch for disabling/enabling asynchronous suspend/resumeRafael J. Wysocki1-0/+13
Add sysfs attribute /sys/power/pm_async allowing the user space to disable/enable asynchronous suspend/resume of devices. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2006-11-03[PATCH] swsusp: debuggingRafael J. Wysocki1-1/+16
Add a swsusp debugging mode. This does everything that's needed for a suspend except for actually suspending. So we can look in the log messages and work out a) what code is being slow and b) which drivers are misbehaving. (1) # echo testproc > /sys/power/disk # echo disk > /sys/power/state This should turn off the non-boot CPU, freeze all processes, wait for 5 seconds and then thaw the processes and the CPU. (2) # echo test > /sys/power/disk # echo disk > /sys/power/state This should turn off the non-boot CPU, freeze all processes, shrink memory, suspend all devices, wait for 5 seconds, resume the devices etc. Cc: Pavel Machek <pavel@ucw.cz> Cc: Stefan Seyfried <seife@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-25PM: add /sys/power documentation to Documentation/ABIRafael J. Wysocki1-0/+88
The file sysfs-power that documents the interface in the /sys/power/ directory is added to Documentation/ABI/testing. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>