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2020-03-06docs: cpu-freq: convert cpufreq-stats.txt to ReSTMauro Carvalho Chehab2-55/+65
- 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 <mchehab+huawei@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-06docs: cpu-freq: convert cpu-drivers.txt to ReSTMauro Carvalho Chehab2-66/+64
- 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 <mchehab+huawei@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-06docs: cpu-freq: convert core.txt to ReSTMauro Carvalho Chehab2-32/+35
- 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 <mchehab+huawei@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-06docs: cpu-freq: convert index.txt to ReSTMauro Carvalho Chehab2-56/+35
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 <mchehab+huawei@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-02Documentation: cpufreq: Move legacy driver documentationRafael J. Wysocki3-264/+0
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@intel.com>
2019-09-02Documentation: cpufreq: Update policy notifier documentationViresh Kumar1-12/+4
Update documentation with the recent policy notifier updates. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-15docs: power: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
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 <mchehab+samsung@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2018-11-07Documentation: cpu-freq: Frequencies aren't always sortedViresh Kumar1-3/+5
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 <pavel2000@ngs.ru> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-10cpufreq: Drop cpufreq_table_validate_and_show()Viresh Kumar2-11/+7
This isn't used anymore. Remove the helper and update documentation accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-08cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()Dominik Brodowski1-0/+4
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 <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-09cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZEGautham R. Shenoy1-0/+3
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 <ego@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-09-28cpufreq: docs: Drop intel-pstate.txt from index.txtRafael J. Wysocki1-2/+0
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@intel.com>
2017-05-14cpufreq: intel_pstate: Document the current behavior and user interfaceRafael J. Wysocki1-281/+0
Add a document describing the current behavior and user space interface of the intel_pstate driver in the RST format and drop the existing outdated intel_pstate.txt document. Also update admin-guide/pm/cpufreq.rst with proper RST references to the new intel_pstate.rst document. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-03-14cpufreq: User/admin documentation update and consolidationRafael J. Wysocki4-629/+0
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 <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-03-09Documentation: cpu-freq: cpu-drivers: Fix repetition of word 'to'sayli karnik1-1/+1
The patch replaces 'to to' with 'to' in the documentation. Signed-off-by: sayli karnik <karniksayli1995@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-02-23Merge tag 'docs-4.11' of git://git.lwn.net/linuxLinus Torvalds1-1/+3
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 ...
2017-02-04cpufreq: intel_pstate: Operation mode control from sysfsRafael J. Wysocki1-0/+15
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@intel.com>
2017-02-04cpufreq: Documentation: Updates based on current codeViresh Kumar6-193/+232
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 <claudio@evidence.eu.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-04cpufreq: Documentation: Minor reformattingViresh Kumar1-93/+112
This patch doesn't change the content of the documentation, but rather reformat it to make it more readable. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-05Note that the POWER[89] processors are supported.Shilpasri G Bhat1-1/+3
Documentation: cpufreq: Update supported powernv processors Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-12-08Documentation: intel_pstate: Document HWP energy/performance hintsSrinivas Pandruvada1-0/+24
Updated documentation for the support of energy performance hint in the HWP mode. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-11cpufreq: stats: New sysfs attribute for clearing statisticsMarkus Mayer1-0/+6
Allow CPUfreq statistics to be cleared by writing anything to /sys/.../cpufreq/stats/reset. Signed-off-by: Markus Mayer <mmayer@broadcom.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-01Documentation: intel_pstate: Update per core limitsSrinivas Pandruvada1-1/+20
Document restriction on per core P-State control. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21Documentation: intel_pstate: PID tuning is not always availableSrinivas Pandruvada1-4/+5
PID tuning is not available when the get_target_pstate_use_cpu_load() is used to calculate target_state. So update the documentation. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-09cpufreq-stats: Minor documentation fixJean Delvare1-1/+1
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 <jdelvare@suse.de> Fixes: 1aefc75b2449 (cpufreq: stats: Make the stats code non-modular) Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-23Revert "cpufreq: pcc-cpufreq: update default value of ↵Andreas Herrmann1-2/+2
cpuinfo_transition_latency" 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: <stable@vger.kernel.org> # 4.5+ Signed-off-by: Andreas Herrmann <aherrmann@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09cpufreq: Return index from cpufreq_frequency_table_target()Viresh Kumar1-4/+3
This routine can't fail unless the frequency table is invalid and doesn't contain any valid entries. Make it return the index and WARN() in case it is used for an invalid table. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09cpufreq: Drop freq-table param to cpufreq_frequency_table_target()Viresh Kumar1-1/+0
The policy already has this pointer set, use it instead. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-03cpufreq: Unexport cpufreq_frequency_table_cpuinfo()Viresh Kumar2-3/+3
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 <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-18Documentation: cpufreq: intel_pstate: fix typoFelipe Franciosi1-1/+1
This just swaps a colon for a quote in the intel_pstate documentation. Signed-off-by: Felipe Franciosi <felipe@nutanix.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-05Documentation: cpufreq: intel_pstate: enhance documentationSrinivas Pandruvada1-42/+199
This is an attempt to make documentation more user friendly. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Doug Smythies <dsmythies@telus.net> Reviewed-by: Chen, Yu C <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latencyJacob Tanenbaum1-2/+2
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 <jtanenba@redhat.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier eventViresh Kumar1-5/+2
What's being done from CPUFREQ_INCOMPATIBLE, can also be done with CPUFREQ_ADJUST. There is nothing special with CPUFREQ_INCOMPATIBLE notifier. Kill CPUFREQ_INCOMPATIBLE and fix its usage sites. This also updates the numbering of notifier events to remove holes. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-25Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6Linus Torvalds2-11/+12
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() ...
2015-06-05Documentation, intel_pstate: Improve legacy mode internal governors descriptionPrarit Bhargava2-11/+12
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 <prarit@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Kristen Carlson Accardi <kristen@linux.intel.com> Cc: Dirk Brandewie <dirk.j.brandewie@intel.com> Cc: x86@kernel.org Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-05-06Documentation: cpufreq: delete duplicate description of sysfs interface ↵Wang Long1-2/+0
'scaling_driver' 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 <long.wanglong@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-30intel_pstate: Add num_pstates to sysfsKristen Carlson Accardi1-0/+4
Add a sysfs interface to display the total number of supported pstates. This value is independent of whether turbo has been enabled or disabled. Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-30intel_pstate: expose turbo range to sysfsKristen Carlson Accardi1-0/+4
This patch adds "turbo_pct" to the intel_pstate sysfs interface. turbo_pct will display the percentage of the total supported pstates that are in the turbo range. This value is independent of whether turbo has been disabled or not. Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-12intel_pstate: Add support for HWPDirk Brandewie1-12/+25
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 <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-07intel_pstate: Update documentation of {max,min}_perf_pct sysfs filesDirk Brandewie1-2/+5
Update documentation to make the interpretation of the values clearer Link: https://bugzilla.kernel.org/show_bug.cgi?id=64251 Cc: 3.13+ <stable@vger.kernel.org> # 3.13+ Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-06cpufreq: add support for intermediate (stable) frequenciesViresh Kumar1-2/+27
Douglas Anderson, recently pointed out an interesting problem due to which udelay() was expiring earlier than it should. While transitioning between frequencies few platforms may temporarily switch to a stable frequency, waiting for the main PLL to stabilize. For example: When we transition between very low frequencies on exynos, like between 200MHz and 300MHz, we may temporarily switch to a PLL running at 800MHz. No CPUFREQ notification is sent for that. That means there's a period of time when we're running at 800MHz but loops_per_jiffy is calibrated at between 200MHz and 300MHz. And so udelay behaves badly. To get this fixed in a generic way, introduce another set of callbacks get_intermediate() and target_intermediate(), only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION unset. get_intermediate() should return a stable intermediate frequency platform wants to switch to, and target_intermediate() should set CPU to that frequency, before jumping to the frequency corresponding to 'index'. Core will take care of sending notifications and driver doesn't have to handle them in target_intermediate() or target_index(). NOTE: ->target_index() should restore to policy->restore_freq in case of failures as core would send notifications for that. Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-07PM / OPP: Move cpufreq specific OPP functions out of generic OPP libraryNishanth Menon1-0/+29
CPUFreq specific helper functions for OPP (Operating Performance Points) now use generic OPP functions that allow CPUFreq to be be moved back into CPUFreq framework. This allows for independent modifications or future enhancements as needed isolated to just CPUFreq framework alone. Here, we just move relevant code and documentation to make this part of CPUFreq infrastructure. Cc: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-01cpufreq: Make linux-pm@vger.kernel.org official mailing listViresh Kumar1-2/+2
There has been confusion all the time about which mailing list to follow for cpufreq activities, linux-pm@vger.kernel.org or cpufreq@vger.kernel.org. Since patches sent to cpufreq@vger.kernel.org don't go to Patchwork which is a maintenance workflow problem, make linux-pm@vger.kernel.org the official mailing list for cpufreq stuff and remove all references of cpufreq@vger.kernel.org from kernel source. Later, we can request that the list be dropped entirely. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-30cpufreq: Introduce macros for cpufreq_frequency_table iterationStratos Karafotis1-0/+19
Many cpufreq drivers need to iterate over the cpufreq_frequency_table for various tasks. This patch introduces two macros which can be used for iteration over cpufreq_frequency_table keeping a common coding style across drivers: - cpufreq_for_each_entry: iterate over each entry of the table - cpufreq_for_each_valid_entry: iterate over each entry that contains a valid frequency. It should have no functional changes. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20cpufreq: Add stop CPU callback to cpufreq_driver interfaceDirk Brandewie1-1/+7
This callback allows the driver to do clean up before the CPU is completely down and its state cannot be modified. This is used by the intel_pstate driver to reduce the requested P state prior to the core going away. This is required because the requested P state of the offline core is used to select the package P state. This effectively sets the floor package P state to the requested P state on the offline core. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> [rjw: Minor modifications] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-19cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}Viresh Kumar1-4/+0
Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have not been used for some time, so remove them to clean up code a bit. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17Documentation: cpufreq / boost: Update BOOST documentationLukasz Majewski1-13/+13
Since the support for software and hardware controlled boosting has been added, update the corresponding documentation. Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-06Documentation / cpufreq: add intel-pstate.txtRamkumar Ramachandra1-0/+40
The Intel P-state driver is currently undocumented. Add some documentation based on the cover-letter sent with the original series. Cc: Dirk Brandewie <dirk.brandewie@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-26cpufreq: Implement light weight ->target_index() routineViresh Kumar2-11/+20
Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-08-10cpufreq: Drop the owner field from struct cpufreq_driverViresh Kumar1-2/+0
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers as this field isn't used any more by the cpufreq core. This patch removes it and updates all dependent drivers accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>