06 Mar, 2020

4 commits

  • - Add a SPDX header;
    - Add a document title, based on the original contents of
    cpu-freq/index.txt;
    - Use lists where needed;
    - Comment out the existing text-only index;
    - Adjust some title marks;
    - Use bold on some places;
    - Mark literal blocks as such;
    - Some whitespace fixes and new line breaks;
    - Add it to cpu-freq/index.rst.

    Signed-off-by: Mauro Carvalho Chehab
    Signed-off-by: Rafael J. Wysocki

    Mauro Carvalho Chehab
     
  • - Add a SPDX header;
    - Add a document title, based on the original contents of
    cpu-freq/index.txt;
    - Use lists where needed;
    - Comment out the existing text-only index;
    - Adjust some title marks;
    - Add table markups;
    - Add notes markups;
    - Mark literal blocks as such;
    - use ``foo`` for literal texts;
    - Some whitespace fixes and new line breaks;
    - Add it to cpu-freq/index.rst.

    Signed-off-by: Mauro Carvalho Chehab
    Signed-off-by: Rafael J. Wysocki

    Mauro Carvalho Chehab
     
  • - Add a SPDX header;
    - Adjust the document title, based on the original contents of
    cpu-freq/index.txt;
    - Use lists where needed;
    - Comment out the existing text-only index;
    - use ``foo`` to mark a literal expression with asterisk;
    - Adjust some title marks;
    - Add table markups;
    - Add notes markups;
    - Some whitespace fixes and new line breaks;
    - Add it to cpu-freq/index.rst.

    Signed-off-by: Mauro Carvalho Chehab
    Signed-off-by: Rafael J. Wysocki

    Mauro Carvalho Chehab
     
  • most of the stuff there can be re-used with ReST format,
    but we need to add an empty TOC and remove the existing
    entries, as the following conversion patches will be re-adding
    them, as they're converted.

    Signed-off-by: Mauro Carvalho Chehab
    Signed-off-by: Rafael J. Wysocki

    Mauro Carvalho Chehab
     

02 Mar, 2020

1 commit

  • There are three legacy driver documents in Documentation/cpu-freq/
    that were added years ago and converting them each to the .rst
    format is rather pointless, even though there is some value in
    preserving them. However, if they are preserved, they need to go
    into the admin-guide part of cpufreq documentation where they belong
    (at least to a certain extent).

    To preserve them with minimum amount of changes and put them into the
    right place, and make it possible to process them into HTML (and other
    formats) along with the rest of the documentation, move them each
    as a "literal text" block into a separate section of a single .rst
    "wrapper" file under Documentation/admin-guide/pm/.

    While at it, repair the PCC specification URL in one of them.

    Signed-off-by: Rafael J. Wysocki

    Rafael J. Wysocki
     

03 Sep, 2019

1 commit


15 Jun, 2019

1 commit

  • Convert the PM documents to ReST, in order to allow them to
    build with Sphinx.

    The conversion is actually:
    - add blank lines and indentation in order to identify paragraphs;
    - fix tables markups;
    - add some lists markups;
    - mark literal blocks;
    - adjust title markups.

    At its new index.rst, let's add a :orphan: while this is not linked to
    the main index.rst file, in order to avoid build warnings.

    Signed-off-by: Mauro Carvalho Chehab
    Signed-off-by: Bjorn Helgaas
    Acked-by: Mark Brown
    Acked-by: Srivatsa S. Bhat (VMware)

    Mauro Carvalho Chehab
     

07 Nov, 2018

1 commit

  • The order in which the frequencies are displayed in cpufreq stats
    depends on the order in which the frequencies were sorted in the
    frequency table provided to cpufreq core by the cpufreq driver. They can
    be completely unsorted as well.

    The documentation's claim that the stats will be sorted in descending
    order is hence incorrect and here is an attempt to fix it.

    Reported-by: Pavel
    Signed-off-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Viresh Kumar
     

10 Apr, 2018

1 commit


08 Feb, 2018

1 commit

  • Pointer subtraction is slow and tedious. Therefore, replace all instances
    where cpufreq_for_each_{valid_,}entry loops contained such substractions
    with an iteration macro providing an index to the frequency_table entry.

    Suggested-by: Al Viro
    Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk
    Acked-by: Viresh Kumar
    Signed-off-by: Dominik Brodowski
    Signed-off-by: Rafael J. Wysocki

    Dominik Brodowski
     

09 Nov, 2017

1 commit

  • On platforms with large number of Pstates, the transition table, which
    is a NxN matrix, can overflow beyond the PAGE_SIZE boundary.

    This can be seen on POWER9 which has 100+ Pstates.

    As a result, each time the trans_table is read for any of the CPUs, we
    will get the following error.

    ---------------------------------------------------
    fill_read_buffer: show+0x0/0xa0 returned bad count
    ---------------------------------------------------

    This patch ensures that in case of an overflow, we print a warning
    once in the dmesg and return FILE TOO LARGE error for this and all
    subsequent accesses of trans_table.

    Signed-off-by: Gautham R. Shenoy
    Acked-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Gautham R. Shenoy
     

28 Sep, 2017

1 commit

  • Commit 33fc30b47098 (cpufreq: intel_pstate: Document the current
    behavior and user interface) dropped the intel-pstate.txt file
    from Documentation/cpu-freq/, but it did not update the index.txt
    file in there accordingly, so do that now.

    Fixes: 33fc30b47098 (cpufreq: intel_pstate: Document the current behavior and user interface)
    Signed-off-by: Rafael J. Wysocki

    Rafael J. Wysocki
     

14 May, 2017

1 commit


14 Mar, 2017

1 commit

  • The user/admin documentation of cpufreq is badly outdated. It
    conains stale and/or inaccurate information along with things
    that are not particularly useful. Also, some of the important
    pieces are missing from it.

    For this reason, add a new user/admin document for cpufreq
    containing current information to admin-guide and drop the old
    outdated .txt documents it is replacing.

    Since there will be more PM documents in admin-guide going forward,
    create a separate directory for them and put the cpufreq document
    in there right away.

    Signed-off-by: Rafael J. Wysocki
    Acked-by: Viresh Kumar
    Signed-off-by: Jonathan Corbet

    Rafael J. Wysocki
     

09 Mar, 2017

1 commit


23 Feb, 2017

1 commit

  • Pull documentation updates from Jonathan Corbet:
    "A slightly quieter cycle for documentation this time around.

    Three more DocBook template files have been converted to RST; only 21
    to go. There are various build improvements and the usual array of
    documentation improvements and fixes"

    * tag 'docs-4.11' of git://git.lwn.net/linux: (44 commits)
    docs / driver-api: Fix structure references in device_link.rst
    PM / docs: Fix structure references in device.rst
    Add a target to check broken external links in the Documentation
    Documentation: Fix linux-api list typo
    Documentation: DocBook/Makefile comment typo
    Improve sparse documentation
    Documentation: make Makefile.sphinx no-ops quieter
    Documentation: DMA-ISA-LPC.txt
    Documentation: input: fix path to input code definitions
    docs: Remove the copyright year from conf.py
    docs: Fix a warning in the Korean HOWTO.rst translation
    PM / sleep / docs: Convert PM notifiers document to reST
    PM / core / docs: Convert sleep states API document to reST
    PM / core: Update kerneldoc comments in pm.h
    doc-rst: Fix recursive make invocation from macros
    doc-rst: Delete output of failed dot-SVG conversion
    doc-rst: Break shell command sequences on failure
    Documentation/sphinx: make targets independent of Sphinx work for HAVE_SPHINX=0
    doc-rst: fixed cleandoc target when used with O=dir
    Documentation/sphinx: prevent generation of .pyc files in the source tree
    ...

    Linus Torvalds
     

04 Feb, 2017

3 commits

  • Make it possible to change the operation mode of intel_pstate with
    the help of a new sysfs attribute called "status".

    There are three possible configurations that can be selected using
    this attribute:

    "off" - The driver is not in use at this time.
    "active" - The driver works as a P-state governor (default).
    "passive" - The driver works as a regular cpufreq one and collaborates
    with the generic cpufreq governors (it sets P-states as
    requested by those governors). [This is the same mode
    the driver can be started in by passing intel_pstate=passive
    in the kernel command line.]

    The current setting is returned by reads from this attribute. Writing
    one of the above strings to it changes the operation mode as indicated
    by that string, if possible.

    If HW-managed P-states (HWP) feature is enabled, it is not possible
    to change the driver's operation mode and attempts to write to this
    attribute will fail.

    Signed-off-by: Rafael J. Wysocki

    Rafael J. Wysocki
     
  • The cpufreq core has gone though lots of updates in recent times, but on
    many occasions the documentation wasn't updated along with the code.
    This patch tries to catchup the documentation with the code.

    Also add Rafael and Viresh as the contributors to the documentation.

    Based on a patch from Claudio Scordino.

    Signed-off-by: Claudio Scordino
    Signed-off-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Viresh Kumar
     
  • This patch doesn't change the content of the documentation, but rather
    reformat it to make it more readable.

    Signed-off-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Viresh Kumar
     

05 Jan, 2017

1 commit


08 Dec, 2016

1 commit


11 Nov, 2016

1 commit


01 Nov, 2016

1 commit


22 Oct, 2016

1 commit


09 Sep, 2016

1 commit

  • The cpufreq-stats code can no longer be built as a module, so it now
    appears with square brackets in menuconfig.

    Signed-off-by: Jean Delvare
    Fixes: 1aefc75b2449 (cpufreq: stats: Make the stats code non-modular)
    Acked-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Jean Delvare
     

23 Jul, 2016

1 commit

  • This reverts commit 790d849bf811a8ab5d4cd2cce0f6fda92f6aebf2.

    Using a v4.7-rc7 kernel on a HP ProLiant triggered following messages

    pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz
    cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor

    The last line was shown for each CPU in the system.
    Testing v4.5 (where commit 790d849b was integrated) triggered
    similar messages. Same behaviour on a 2nd HP Proliant system.

    So commit 790d849bf (cpufreq: pcc-cpufreq: update default value of
    cpuinfo_transition_latency) causes the system to use performance
    governor which, I guess, was not the intention of the patch.

    Enabling debug output in pcc-cpufreq provides following verbose output:

    pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz
    pcc_get_offset: for CPU 0: pcc_cpu_data input_offset: 0x44, pcc_cpu_data output_offset: 0x48
    init: policy->max is 2800000, policy->min is 1200000
    get: get_freq for CPU 0
    get: SUCCESS: (virtual) output_offset for cpu 0 is 0xffffc9000d7c0048, contains a value of: 0xff06. Speed is: 168000 MHz
    cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor
    target: CPU 0 should go to target freq: 2800000 (virtual) input_offset is 0xffffc9000d7c0044
    target: was SUCCESSFUL for cpu 0

    I am asking to revert 790d849bf to re-enable usage of ondemand
    governor with pcc-cpufreq.

    Fixes: 790d849bf (cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency)
    CC: # 4.5+
    Signed-off-by: Andreas Herrmann
    Signed-off-by: Rafael J. Wysocki

    Andreas Herrmann
     

09 Jun, 2016

2 commits


03 Jun, 2016

1 commit

  • All cpufreq drivers with a freq-table are migrated to use
    cpufreq_table_validate_and_show() long back and the routine
    cpufreq_frequency_table_cpuinfo() isn't used outside of cpufreq core
    now.

    Unexport it and update Documentation as well.

    Signed-off-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Viresh Kumar
     

19 Feb, 2016

1 commit


05 Jan, 2016

1 commit


10 Dec, 2015

1 commit

  • The cpufreq documentation specifies

    policy->cpuinfo.transition_latency the time it takes on this CPU to
    switch between two frequencies in
    nanoseconds (if appropriate, else
    specify CPUFREQ_ETERNAL)

    currently pcc-cpufreq does not expose the value and sets it to zero. I
    changed the pcc-cpufreq driver and it's documentation to conform to the
    default value specified in Documentation/cpu-freq/cpu-drivers.txt

    Signed-off-by: Jacob Tanenbaum
    Acked-by: Viresh Kumar
    Signed-off-by: Rafael J. Wysocki

    Jacob Tanenbaum
     

01 Sep, 2015

1 commit


25 Jun, 2015

1 commit

  • Pull documentation updates from Jonathan Corbet:
    "The main thing here is Ingo's big subdirectory documenting feature
    support for each architecture. Beyond that, it's the usual pile of
    fixes, tweaks, and small additions"

    * tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (79 commits)
    doc:md: fix typo in md.txt.
    Documentation/mic/mpssd: don't build x86 userspace when cross compiling
    Documentation/prctl: don't build tsc tests when cross compiling
    Documentation/vDSO: don't build tests when cross compiling
    Doc:ABI/testing: Fix typo in sysfs-bus-fcoe
    Doc: Docbook: Change wikipedia's URL from http to https in scsi.tmpl
    Doc: Change wikipedia's URL from http to https
    Documentation/kernel-parameters: add missing pciserial to the earlyprintk
    Doc:pps: Fix typo in pps.txt
    kbuild : Fix documentation of INSTALL_HDR_PATH
    Documentation: filesystems: updated struct file_operations documentation in vfs.txt
    kbuild: edit explanation of clean-files variable
    Doc: ja_JP: Fix typo in HOWTO
    Move freefall program from Documentation/ to tools/
    Documentation: ARM: EXYNOS: Describe boot loaders interface
    Doc:nfc: Fix typo in nfc-hci.txt
    vfs: Minor documentation fix
    Doc: networking: txtimestamp: fix printf format warning
    Documentation, intel_pstate: Improve legacy mode internal governors description
    Documentation: extend use case for EXPORT_SYMBOL_GPL()
    ...

    Linus Torvalds
     

05 Jun, 2015

1 commit

  • The current documentation is incomplete wrt the intel_pstate legacy
    internal governors. The confusion comes from the general cpufreq
    governors which also use the names performance and powersave. This patch
    better differentiates between the two sets of governors and gives an
    explanation of how the internal P-state governors behave differently from
    one another.

    Also fix two minor typos.

    Cc: Prarit Bhargava
    Cc: "Rafael J. Wysocki"
    Cc: Kristen Carlson Accardi
    Cc: Dirk Brandewie
    Cc: x86@kernel.org
    Acked-by: Viresh Kumar
    Signed-off-by: Prarit Bhargava
    Signed-off-by: Jonathan Corbet

    Prarit Bhargava
     

06 May, 2015

1 commit

  • The file 'Documentation/cpu-freq/user-guide.txt' has duplicate
    description of sysfs interface 'scaling_driver'.

    [first]
    scaling_driver : this file shows what cpufreq driver is
    used to set the frequency on this CPU

    [second]
    scaling_driver : Hardware driver for cpufreq.

    Although this does not affect anything, I think we should only have
    one. so delete the second one because the first one is described in
    more detail.

    Signed-off-by: Wang Long
    Signed-off-by: Rafael J. Wysocki

    Wang Long
     

30 Jan, 2015

2 commits


12 Nov, 2014

1 commit

  • Add support of Hardware Managed Performance States (HWP) described in Volume 3
    section 14.4 of the SDM.

    With HWP enbaled intel_pstate will no longer be responsible for selecting P
    states for the processor. intel_pstate will continue to register to
    the cpufreq core as the scaling driver for CPUs implementing
    HWP. In HWP mode intel_pstate provides three functions reporting
    frequency to the cpufreq core, support for the set_policy() interface
    from the core and maintaining the intel_pstate sysfs interface in
    /sys/devices/system/cpu/intel_pstate. User preferences expressed via
    the set_policy() interface or the sysfs interface are forwared to the
    CPU via the HWP MSR interface.

    Signed-off-by: Dirk Brandewie
    Signed-off-by: Rafael J. Wysocki

    Dirk Brandewie
     

07 Jul, 2014

1 commit