Changes in sysfs-class-devfreq

08e23d05 - PM / devfreq: Fix buffer overflow in trans_stat_show

Tue, 24 Oct 2023 18:30:15 +0000

PM / devfreq: Fix buffer overflow in trans_stat_showFix buffer overflow in trans_stat_show().Convert simple snprintf to the more secure scnprintf with size ofPAGE_SIZE.Add condition checking if we are exceeding PAGE_SIZE and exit early fromloop. Also add at the end a warning that we exceeded PAGE_SIZE and thatstats is disabled.Return -EFBIG in the case where we don't have enough space to write thefull transition table.Also document in the ABI that this function can return -EFBIG error.Link: https://lore.kernel.org/all/20231024183016.14648-2-ansuelsmth@gmail.com/Cc: stable@vger.kernel.orgCloses: https://bugzilla.kernel.org/show_bug.cgi?id=218041Fixes: e552bbaf5b98 ("PM / devfreq: Add sysfs node for representing frequency transition information.")Signed-off-by: Christian Marangi Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

05f15314 - PM / devfreq: Remove the invalid description for get_target_freq

Tue, 23 Mar 2021 07:20:09 +0000

PM / devfreq: Remove the invalid description for get_target_freqFirst of all, no_central_polling was removed sincecommit 7e6fdd4bad03 ("PM / devfreq: Core updates to support deviceswhich can idle")Secondly, get_target_freq() is not only called only with update_devfreq()notified by OPP now, but also min/max freq qos notifier.So remove this invalid description now to avoid confusing.Signed-off-by: Dong Aisheng Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

002a9c2f - docs: ABI: fix syntax to be parsed using ReST notation

Fri, 30 Oct 2020 07:40:47 +0000

docs: ABI: fix syntax to be parsed using ReST notationThere are a number of new changes at the ABI files that causethem to produce warnings when generating ABI output.Fix them.Acked-by: Jonathan Corbet Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/55a89f423cf122982c462d257722e44d6ece4b36.1604042072.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

5f1a9066 - PM / devfreq: Add governor attribute flag for specifc sysfs nodes

Fri, 03 Jul 2020 08:20:27 +0000

PM / devfreq: Add governor attribute flag for specifc sysfs nodesDEVFREQ supports the default governors like performance, simple_ondemand andalso allows the devfreq driver to add their own governor like tegra30-devfreq.caccording to their requirement. In result, some sysfs attributes are usefulor not useful. Prior to that the user can access all sysfs attributesregardless of the available attributes.So, clarify the access permission of sysfs attributes according to governor.When adding the devfreq governor, can specify the available attributeinformation by using DEVFREQ_GOV_ATTR_* constant variable. The user canread or write the sysfs attributes in accordance to the specified attributes.When adding the governor, can add the following attributesaccording to the governor feature.[Definition for speific sysfs attributes]- DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer. : /sys/class/devfreq/[devfreq dev name]/polling_interval- DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable or dealyed timer. : /sys/class/devfreq/[devfreq dev name]/timerAnd all devfreq governors have to support the following common attributes.The common attributes are added to devfreq class by default.- governor- available_governors- available_frequencies- cur_freq- target_freq- min_freq- max_freq- trans_stat[Table of governor attribute flags for devfreq governors]------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| |------------------------------------------------------------------------------governor | O | O | O | O | O | Oavailable_governors | O | O | O | O | O | Oavailable_frequencies | O | O | O | O | O | Ocur_freq | O | O | O | O | O | Otarget_freq | O | O | O | O | O | Omin_freq | O | O | O | O | O | Omax_freq | O | O | O | O | O | Otrans_stat | O | O | O | O | O | O --------------------------------------------------------polling_interval | O | X | X | X | X | Otimer | O | X | X | X | X | X------------------------------------------------------------------------------Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

4dc3bab8 - PM / devfreq: Add support delayed timer for polling mode

Thu, 02 Jul 2020 11:41:28 +0000

PM / devfreq: Add support delayed timer for polling modeUntil now, the devfreq driver using polling mode like simple_ondemandgovernor have used only deferrable timer for reducing the redundantpower consumption. It reduces the CPU wake-up from idle due to polling modewhich check the status of Non-CPU device.But, it has a problem for Non-CPU device like DMC device with DMA operation.Some Non-CPU device need to do monitor continuously regardless of CPU statein order to decide the proper next status of Non-CPU device.So, add support the delayed timer for polling mode to supportthe repetitive monitoring. The devfreq driver and user can selectthe kind of timer on either deferrable and delayed timer.For example, change the timer type of DMC devicebased on Exynos5422-based Odroid-XU3 as following:- If want to use deferrable timer as following:echo deferrable > /sys/class/devfreq/10c20000.memory-controller/timer- If want to use delayed timer as following:echo delayed > /sys/class/devfreq/10c20000.memory-controller/timerReviewed-by: Bartlomiej Zolnierkiewicz Reviewed-by: Lukasz Luba Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

14a34396 - PM / devfreq: Add clearing transitions stats

Thu, 05 Dec 2019 14:55:26 +0000

PM / devfreq: Add clearing transitions statsAdd clearing transition table and time in states devfreq statisticsby writing 0 (zero) to trans_stat file in devfreq sysfs. An example useis like following:echo 0 > /sys/class/devfreq/devfreqX/trans_statSigned-off-by: Kamil Konieczny [cw00.choi: Edit return value if entering the wrong value for reset and use arrary3_size() to get the size of 3-dimensional array]Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

2fee1a7c - PM / devfreq: Add new name attribute for sysfs

Tue, 05 Nov 2019 09:18:03 +0000

PM / devfreq: Add new name attribute for sysfsThe commit 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) forsysfs") changed the node name to devfreq(x). After this commit, it is notpossible to get the device name through /sys/class/devfreq/devfreq(X)/*.Add new name attribute in order to get device name.Cc: stable@vger.kernel.orgFixes: 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")Signed-off-by: Chanwoo Choi List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

ed66bcd0 - ABI: fix some syntax issues at the ABI database

Fri, 14 Jun 2019 02:04:07 +0000

ABI: fix some syntax issues at the ABI databaseOn those three files, the ABI representation described atREADME are violated.- at sysfs-bus-iio-proximity-as3935: a ':' character is missing after "What"- at sysfs-class-devfreq: there's a typo at Description- at sysfs-class-cxl, it is using the ":" character at a file preamble, causing it to be misinterpreted as a tag.- On the other files, instead of "What", they use "Where".Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Mauro Carvalho Chehab Acked-by: Rafael J. Wysocki Acked-by: Andrew Donnellan # cxlSigned-off-by: Greg Kroah-Hartman List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

de9c7394 - PM / devfreq: add comments and Documentation

Tue, 05 Feb 2013 09:40:17 +0000

PM / devfreq: add comments and Documentation- Added missing ABI documents- Added comments to clarify the objectives of functionsSigned-off-by: MyungJoo Ham Acked-by: Nishanth Menon Acked-by: Rajagopal Venkat List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

50a5b33e - PM / devfreq: Add sysfs node to expose available governors

Mon, 29 Oct 2012 20:01:48 +0000

PM / devfreq: Add sysfs node to expose available governorsNow that governor list can be variable, knowing the available governorsis useful to be able to select a governor using relevant sysfs node.Cc: Rajagopal Venkat Cc: MyungJoo Ham Cc: Kyungmin Park Cc: "Rafael J. Wysocki" Cc: Kevin Hilman Cc: linux-pm@vger.kernel.orgCc: linux-kernel@vger.kernel.orgSigned-off-by: Nishanth Menon Signed-off-by: MyungJoo Ham List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

0359d1af - PM / devfreq: allow sysfs governor node to switch governor

Mon, 29 Oct 2012 20:01:47 +0000

PM / devfreq: allow sysfs governor node to switch governorThis allows us to select governor runtime from thedefault configuration without having to rebuild kernelor the devfreq driver using the sysfs node:/sys/class/devfreq/.../governorcat of the governor will return valid governorand an echo 'governor_name'>governor will switchgovernorCc: Rajagopal Venkat Cc: MyungJoo Ham Cc: Kyungmin Park Cc: "Rafael J. Wysocki" Cc: Kevin Hilman Cc: linux-pm@vger.kernel.orgCc: linux-kernel@vger.kernel.orgSigned-off-by: Nishanth Menon Acked-by: MyungJoo Ham Signed-off-by: MyungJoo Ham List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

e552bbaf - PM / devfreq: Add sysfs node for representing frequency transition information.

Thu, 23 Aug 2012 11:00:46 +0000

PM / devfreq: Add sysfs node for representing frequency transition information.This patch adds sysfs node which can be used to get information of frequencytransition. It represents transition table which contains total number of transition ofeach freqeuncy state and time spent. It is inspired CPUFREQ's status driver.Signed-off-by: Jonghwa Lee [Added Documentation/ABI entry, updated kernel-doc, and resolved merge conflict]Signed-off-by: MyungJoo Ham List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

d287de85 - PM / devfreq: Add sysfs node to expose available frequencies

Fri, 26 Oct 2012 00:48:59 +0000

PM / devfreq: Add sysfs node to expose available frequenciesdevfreq governors such as ondemand are controlled by a min andmax frequency, while governors like userspace governor allow usto set a specific frequency.However, for the same specific device, depending on the SoC, theavailable frequencies can vary.So expose the available frequencies as a snapshot over sysfs toallow informed decisions.This was inspired by cpufreq framework's equivalent for similarusage sysfs node: scaling_available_frequencies.Cc: Rajagopal Venkat Cc: MyungJoo Ham Cc: Kyungmin Park Cc: "Rafael J. Wysocki" Cc: Kevin Hilman Cc: linux-pm@vger.kernel.orgCc: linux-kernel@vger.kernel.orgSigned-off-by: Nishanth Menon Signed-off-by: MyungJoo Ham List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

7f98a905 - PM / devfreq: Add current freq callback in device profile

Thu, 25 Oct 2012 23:50:26 +0000

PM / devfreq: Add current freq callback in device profileDevfreq returns governor predicted frequency as current frequencyvia sysfs interface. But device may not support all frequenciesthat governor predicts. So add a callback in device profile to getcurrent freq from driver. Also add a new sysfs node to exposegovernor predicted next target frequency.Signed-off-by: Rajagopal Venkat Acked-by: MyungJoo Ham Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

7e6fdd4b - PM / devfreq: Core updates to support devices which can idle

Thu, 25 Oct 2012 23:50:09 +0000

PM / devfreq: Core updates to support devices which can idlePrepare devfreq core framework to support devices whichcan idle. When device idleness is detected perhaps throughruntime-pm, need some mechanism to suspend devfreq loadmonitoring and resume back when device is online. Presentcode continues monitoring unless device is removed fromdevfreq core.This patch introduces following design changes, - use per device work instead of global work to monitor device load. This enables suspend/resume of device devfreq and reduces monitoring code complexity. - decouple delayed work based load monitoring logic from core by introducing helpers functions to be used by governors. This provides flexibility for governors either to use delayed work based monitoring functions or to implement their own mechanism. - devfreq core interacts with governors via events to perform specific actions. These events include start/stop devfreq. This sets ground for adding suspend/resume events.The devfreq apis are not modified and are kept intact.Signed-off-by: Rajagopal Venkat Acked-by: MyungJoo Ham Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

ce26c5bb - PM / devfreq: Add basic governors

Sat, 01 Oct 2011 22:19:34 +0000

PM / devfreq: Add basic governorsFour cpufreq-like governors are provided as examples.powersave: use the lowest frequency possible. The user (device) shouldset the polling_ms as 0 because polling is useless for this governor.performance: use the highest freqeuncy possible. The user (device)should set the polling_ms as 0 because polling is useless for thisgovernor.userspace: use the user specified frequency stored atdevfreq.user_set_freq. With sysfs support in the following patch, a usermay set the value with the sysfs interface.simple_ondemand: simplified version of cpufreq's ondemand governor.When a user updates OPP entries (enable/disable/add), OPP frameworkautomatically notifies devfreq to update operating frequencyaccordingly. Thus, devfreq users (device drivers) do not need to updatedevfreq manually with OPP entry updates or set polling_ms for powersave, performance, userspace, or any other "static" governors.Note that these are given only as basic examples for governors and anydevices with devfreq may implement their own governors with the driversand use them.Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Reviewed-by: Mike Turquette Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq

9005b650 - PM / devfreq: Add common sysfs interfaces

Sat, 01 Oct 2011 22:19:28 +0000

PM / devfreq: Add common sysfs interfacesDevice specific sysfs interface /sys/devices/.../power/devfreq_*- governor R: name of governor- cur_freq R: current frequency- polling_interval R: polling interval in ms given with devfreq profile W: update polling interval.- central_polling R: 1 if polling is managed by devfreq frameworkSigned-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Reviewed-by: Mike Turquette Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki -- Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++ drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-devfreq