Changes in sysfs-devices-power

b18ee4a4 - sysfs docs: ABI: Fix typo in comment

Thu, 21 Jul 2022 02:06:23 +0000

sysfs docs: ABI: Fix typo in commentFix typo in the commentSigned-off-by: Slark Xiao Link: https://lore.kernel.org/r/20220721020623.20974-1-slark_xiao@163.comSigned-off-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

5e588088 - ABI: sysfs-devices-power: add some debug sysfs files

Mon, 27 Sep 2021 13:59:42 +0000

ABI: sysfs-devices-power: add some debug sysfs filesThose files were added back in Apr 2010, but there's nodocumentation for them yet.Fixes: c92445fadb91 ("PM / Runtime: Add sysfs debug files")Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/df6c3ae0ffc2dddf73d7a5baf696a4aa260fb576.1632750608.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

405ea445 - ABI: sysfs-devices-power: document some RPM statistics

Mon, 27 Sep 2021 13:59:37 +0000

ABI: sysfs-devices-power: document some RPM statisticsChangeset 8d4b9d1bfef1 ("PM / Runtime: Add runtime PM statistics (v3)")added runtime_active_time and runtime_suspended_time, in orderto allow powertop to identify the amount of time a device isactive/suspended.Add an ABI description for those.Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/d5524b966d081c650121c4c496c2f7ab3df524e9.1632750608.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

0760bb9a - PM: runtime: Documentation: add runtime_status ABI document

Tue, 03 Sep 2019 13:12:22 +0000

PM: runtime: Documentation: add runtime_status ABI document/sys/devices/.../power/runtime_status is introduced by commit c92445fadb91("PM / Runtime: Add sysfs debug files"). Then commit 0fcb4eef8294 ("PM /Runtime: Make runtime_status attribute not debug-only (v. 2)") made theruntime_status attribute available without CONFIG_PM_ADVANCED_DEBUG.This adds missing runtime_status ABI document.Signed-off-by: Akinobu Mita Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

0759e80b - PM / QoS: Fix device resume latency framework

Tue, 07 Nov 2017 10:33:49 +0000

PM / QoS: Fix device resume latency frameworkThe special value of 0 for device resume latency PM QoS means"no restriction", but there are two problems with that.First, device resume latency PM QoS requests with 0 as thevalue are always put in front of requests with positivevalues in the priority lists used internally by the PM QoSframework, causing 0 to be chosen as an effective constraintvalue. However, that 0 is then interpreted as "no restriction"effectively overriding the other requests with specificrestrictions which is incorrect.Second, the users of device resume latency PM QoS have noway to specify that *any* resume latency at all should beavoided, which is an artificial limitation in general.To address these issues, modify device resume latency PM QoS touse S32_MAX as the "no constraint" value and 0 as the "nolatency at all" one and rework its users (the cpuidle menugovernor, the genpd QoS governor and the runtime PM framework)to follow these changes.Also add a special "n/a" value to the corresponding user space I/Fto allow user space to indicate that it cannot accept any resumelatencies at all for the given device.Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints)Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323Reported-by: Reinette Chatre Signed-off-by: Rafael J. Wysocki Tested-by: Reinette Chatre Tested-by: Geert Uytterhoeven Tested-by: Tero Kristo Reviewed-by: Ramesh Thomas List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

d5919dcc - Revert "PM / QoS: Fix device resume latency PM QoS"

Tue, 31 Oct 2017 17:26:15 +0000

Revert "PM / QoS: Fix device resume latency PM QoS"This reverts commit 0cc2b4e5a020 (PM / QoS: Fix device resume latency PMQoS) as it introduced regressions on multiple systems and the fix-upin commit 2a9a86d5c813 (PM / QoS: Fix default runtime_pm device resumelatency) does not address all of them.The original problem that commit 0cc2b4e5a020 was attempting to fixwill be addressed later.Fixes: 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS)Reported-by: Geert Uytterhoeven Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

0cc2b4e5 - PM / QoS: Fix device resume latency PM QoS

Tue, 24 Oct 2017 13:20:45 +0000

PM / QoS: Fix device resume latency PM QoSThe special value of 0 for device resume latency PM QoS means"no restriction", but there are two problems with that.First, device resume latency PM QoS requests with 0 as thevalue are always put in front of requests with positivevalues in the priority lists used internally by the PM QoSframework, causing 0 to be chosen as an effective constraintvalue. However, that 0 is then interpreted as "no restriction"effectively overriding the other requests with specificrestrictions which is incorrect.Second, the users of device resume latency PM QoS have noway to specify that *any* resume latency at all should beavoided, which is an artificial limitation in general.To address these issues, modify device resume latency PM QoS touse S32_MAX as the "no constraint" value and 0 as the "nolatency at all" one and rework its users (the cpuidle menugovernor, the genpd QoS governor and the runtime PM framework)to follow these changes.Also add a special "n/a" value to the corresponding user space I/Fto allow user space to indicate that it cannot accept any resumelatencies at all for the given device.Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints)Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323Reported-by: Reinette Chatre Tested-by: Reinette Chatre Signed-off-by: Rafael J. Wysocki Acked-by: Alex Shi Cc: All applicable List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

20f97caf - PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUP

Fri, 13 Oct 2017 13:27:24 +0000

PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUPThe PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistentlyand the vast majority of code simply assumes that remote wakeupshould be enabled for devices in runtime suspend if they cangenerate wakeup signals, so drop it.Signed-off-by: Rafael J. Wysocki Acked-by: Ulf Hansson Reviewed-by: Mika Westerberg List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

d0549801 - PM / wakeup: Correct presence vs. emptiness of wakeup_* attributes

Fri, 28 Mar 2014 10:15:14 +0000

PM / wakeup: Correct presence vs. emptiness of wakeup_* attributesAccording to the documentation, the various wakeup_* attributes in sysfsare not present if the device is not enabled to wake up the system.This is not correct: the attributes are not present if the device is notcapable to wake up the system. They are empty if the device is not enabledto wake up the system.Signed-off-by: Geert Uytterhoeven Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

2d984ad1 - PM / QoS: Introcuce latency tolerance device PM QoS type

Mon, 10 Feb 2014 23:35:38 +0000

PM / QoS: Introcuce latency tolerance device PM QoS typeAdd a new latency tolerance device PM QoS type to be use forspecifying active state (RPM_ACTIVE) memory access (DMA) latencytolerance requirements for devices. It may be used to preventhardware from choosing overly aggressive energy-saving operationmodes (causing too much latency to appear) for the whole platform.This feature reqiures hardware support, so it only will beavailable for devices having a new .set_latency_tolerance()callback in struct dev_pm_info populated, in which case theroutine pointed to by it should implement whatever is necessaryto transfer the effective requirement value to the hardware.Whenever the effective latency tolerance changes for the device,its .set_latency_tolerance() callback will be executed and theeffective value will be passed to it. If that value is negative,which means that the list of latency tolerance requirements forthe device is empty, the callback is expected to switch theunderlying hardware latency tolerance control mechanism to anautonomous mode if available. If that value is PM_QOS_LATENCY_ANY,in turn, and the hardware supports a special "no requirement"setting, the callback is expected to use it. That allows softwareto prevent the hardware from automatically updating the device'slatency tolerance in response to its power state changes (e.g. duringtransitions from D3cold to D0), which generally may be done in theautonomous latency tolerance control mode.If .set_latency_tolerance() is present for the device, a newpm_qos_latency_tolerance_us attribute will be present in thedevivce's power directory in sysfs. Then, user space can usethat attribute to specify its latency tolerance requirement forthe device, if any. Writing "any" to it means "no requirement, butdo not let the hardware control latency tolerance" and writing"auto" to it allows the hardware to be switched to the autonomousmode if there are no other requirements from the kernel side in thedevice's list.This changeset includes a fix from Mika Westerberg.Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

49db1903 - MAINTAINERS / Documentation: Update Rafael's e-mail address

Tue, 08 Oct 2013 23:47:53 +0000

MAINTAINERS / Documentation: Update Rafael's e-mail addressThe e-mail address rjw@sisk.pl that I have been using for quite sometime 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 List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

4e79162a - doc: fix quite a few typos within Documentation

Thu, 08 Nov 2012 12:57:35 +0000

doc: fix quite a few typos within DocumentationCorrect spelling typo in DocumentationsSigned-off-by: Jiri Kosina List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

e39473d0 - PM / QoS: Make it possible to expose PM QoS device flags to user space

Wed, 24 Oct 2012 00:08:18 +0000

PM / QoS: Make it possible to expose PM QoS device flags to user spaceDefine two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFFand PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routinesdev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing thecaller to expose those two flags to user space or to hide themfrom it, respectively.After the flags have been exposed, user space will see twoadditional sysfs attributes, pm_qos_no_power_off andpm_qos_remote_wakeup, under the device's /sys/devices/.../power/directory. Then, writing 1 to one of them will update thePM QoS flags request owned by user space so that the correspondingflag is requested to be set. In turn, writing 0 to one of themwill cause the corresponding flag in the user space's request tobe cleared (however, the owners of the other PM QoS flags requestsfor the same device may still request the flag to be set and itmay be effectively set even if user space doesn't request that).Signed-off-by: Rafael J. Wysocki Reviewed-by: Jean Pihet Acked-by: mark gross List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

55850945 - PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources

Sun, 29 Apr 2012 20:53:32 +0000

PM / Sleep: Add "prevent autosleep time" statistics to wakeup sourcesAndroid uses one wakelock statistics that is only necessary foropportunistic sleep. Namely, the prevent_suspend_time fieldaccumulates the total time the given wakelock has been lockedwhile "automatic suspend" was enabled. Add an analogous field,prevent_sleep_time, to wakeup sources and make it behave in a similarway.Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

30e3ce6d - PM / Sleep: Change wakeup source statistics to follow Android

Sun, 29 Apr 2012 20:52:52 +0000

PM / Sleep: Change wakeup source statistics to follow AndroidWakeup statistics used by Android are slightly different from what wehave in wakeup sources at the moment and there aren't any knownusers of those statistics other than Android, so modify them to makeit easier for Android to switch to wakeup sources.This removes the struct wakeup_source's hit_cout field, which is veryrough and therefore not very useful, and adds two new fields,wakeup_count and expire_count. The first one tracks how many timesthe wakeup source is activated with events_check_enabled set (whichroughly corresponds to the situations when a system power transitionto a sleep state is in progress and would be aborted by this wakeupsource if it were the only active one at that time) and the secondone is the number of times the wakeup source has been activated witha timeout that expired.Additionally, the last_time field is now updated when the wakeupsource is deactivated too (previously it was only updated duringthe wakeup source's activation), which seems to be what Android doeswith the analogous counter for wakelocks.Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

85dc0b8a - PM / QoS: Make it possible to expose PM QoS latency constraints

Tue, 13 Mar 2012 00:01:39 +0000

PM / QoS: Make it possible to expose PM QoS latency constraintsA runtime suspend of a device (e.g. an MMC controller) belonging toa power domain or, in a more complicated scenario, a runtime suspendof another device in the same power domain, may cause power to beremoved from the entire domain. In that case, the amount of timenecessary to runtime-resume the given device (e.g. the MMCcontroller) is often substantially greater than the time needed torun its driver's runtime resume callback. That may hurt performancein some situations, because user data may need to wait for thedevice to become operational, so we should make it possible toprevent that from happening.For this reason, introduce a new sysfs attribute for devices,power/pm_qos_resume_latency_us, allowing user space to specify theupper bound of the time necessary to bring the (runtime-suspended)device up after the resume of it has been requested. However, makethat attribute appear only for the devices whose drivers declaresupport for it by calling the (new) dev_pm_qos_expose_latency_limit()helper function with the appropriate initial value of the attribute.Signed-off-by: Rafael J. Wysocki Reviewed-by: Kevin Hilman Reviewed-by: Mark Brown Acked-by: Linus Walleij List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

cb8f51bd - PM: Do not create wakeup sysfs files for devices that cannot wake up

Tue, 08 Feb 2011 22:26:02 +0000

PM: Do not create wakeup sysfs files for devices that cannot wake upCurrently, wakeup sysfs attributes are created for all devices,regardless of whether or not they are wakeup-capable. This isexcessive and complicates wakeup device identification from userspace (i.e. to identify wakeup-capable devices user space has to read/sys/devices/.../power/wakeup for all devices and see if they are notempty).Fix this issue by avoiding to create wakeup sysfs files for devicesthat cannot wake up the system from sleep states (i.e. whosepower.can_wakeup flags are unset during registration) and modifydevice_set_wakeup_capable() so that it adds (or removes) the relevantsysfs attributes if a device's wakeup capability status is changed.Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

15bcb91d - PM / Runtime: Implement autosuspend support

Sat, 25 Sep 2010 21:35:21 +0000

PM / Runtime: Implement autosuspend supportThis patch (as1427) implements the "autosuspend" facility for runtimePM. A few new fields are added to the dev_pm_info structure andseveral new PM helper functions are defined, for telling the PM corewhether or not a device uses autosuspend, for setting the autosuspenddelay, and for marking periods of device activity.Drivers that do not want to use autosuspend can continue using thesame helper functions as before; their behavior will not change. Inaddition, drivers supporting autosuspend can also call the old helperfunctions to get the old behavior.The details are all explained in Documentation/power/runtime_pm.txtand Documentation/ABI/testing/sysfs-devices-power.Signed-off-by: Alan Stern Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

074037ec - PM / Wakeup: Introduce wakeup source objects and event statistics (v3)

Wed, 22 Sep 2010 20:09:10 +0000

PM / Wakeup: Introduce wakeup source objects and event statistics (v3)Introduce struct wakeup_source for representing system wakeup sourceswithin the kernel and for collecting statistics related to them.Make the recently introduced helper functions pm_wakeup_event(),pm_stay_awake() and pm_relax() use struct wakeup_source objectsinternally, so that wakeup statistics associated with wakeup devicescan be collected and reported in a consistent way (the definition ofpm_relax() is changed, which is harmless, because this function isnot called directly by anyone yet). Introduce new wakeup-relatedsysfs device attributes in /sys/devices/.../power for reporting thedevice wakeup statistics.Change the global wakeup events counters event_count andevents_in_progress into atomic variables, so that it is not necessaryto acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()and pm_relax(), which should allow us to avoid lock contention inthese functions on SMP systems with many wakeup devices.Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power

5a2eb858 - PM: Add facility for advanced testing of async suspend/resume

Sat, 23 Jan 2010 21:25:23 +0000

PM: Add facility for advanced testing of async suspend/resumeAdd configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling inextra PM debugging/testing code allowing one to access somePM-related attributes of devices from the user space via sysfs.If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/asyncfor every device allowing the user space to access the device'spower.async_suspend flag and modify it, if desired.Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-power