linux-toradex.git/Documentation/cpu-freq, branch v4.4.155

cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event

2015-09-01T13:50:38+00:00

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 
Signed-off-by: Rafael J. Wysocki

Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6

2015-06-25T03:01:36+00:00

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()
  ...

Documentation, intel_pstate: Improve legacy mode internal governors description

2015-06-04T22:48:57+00:00

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

Documentation: cpufreq: delete duplicate description of sysfs interface 'scaling_driver'

2015-05-05T21:23:25+00:00

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

intel_pstate: Add num_pstates to sysfs

2015-01-30T00:52:17+00:00

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 
Signed-off-by: Rafael J. Wysocki

intel_pstate: expose turbo range to sysfs

2015-01-30T00:52:17+00:00

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 
Signed-off-by: Rafael J. Wysocki

intel_pstate: Add support for HWP

2014-11-11T23:04:38+00:00

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

intel_pstate: Update documentation of {max,min}_perf_pct sysfs files

2014-07-06T23:22:19+00:00

Update documentation to make the interpretation of the values clearer

Link: https://bugzilla.kernel.org/show_bug.cgi?id=64251
Cc: 3.13+   # 3.13+
Signed-off-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki

cpufreq: add support for intermediate (stable) frequencies

2014-06-05T21:32:29+00:00

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 
Signed-off-by: Viresh Kumar 
Reviewed-by: Doug Anderson 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Move cpufreq specific OPP functions out of generic OPP library

2014-05-06T22:39:03+00:00

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 
Signed-off-by: Nishanth Menon 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki