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Merge tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/…
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Pull power management fixes from Rafael Wysocki:
 "These fix RTC wakeup from suspend-to-idle broken recently, fix CPU
  idleness detection condition in the schedutil cpufreq governor, fix a
  cpufreq driver build failure, fix an error code path in the power
  capping framework, clean up the hibernate core and update the
  intel_pstate documentation.

  Specifics:

   - Fix RTC wakeup from suspend-to-idle broken by the recent rework of
     ACPI wakeup handling (Rafael Wysocki).

   - Update intel_pstate driver documentation to reflect the current
     code and explain how it works in more detail (Rafael Wysocki).

   - Fix an issue related to CPU idleness detection on systems with
     shared cpufreq policies in the schedutil governor (Juri Lelli).

   - Fix a possible build issue in the dbx500 cpufreq driver (Arnd
     Bergmann).

   - Fix a function in the power capping framework core to return an
     error code instead of 0 when there's an error (Dan Carpenter).

   - Clean up variable definition in the hibernation core (Pushkar
     Jambhlekar)"

* tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: dbx500: add a Kconfig symbol
  PM / hibernate: Declare variables as static
  PowerCap: Fix an error code in powercap_register_zone()
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()
  cpufreq: intel_pstate: Document the current behavior and user interface
  cpufreq: schedutil: use now as reference when aggregating shared policy requests
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Linus Torvalds committed May 23, 2017
2 parents ad258fb + bb47e96 commit 801099b
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19 changes: 10 additions & 9 deletions Documentation/admin-guide/pm/cpufreq.rst
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
.. |struct cpufreq_policy| replace:: :c:type:`struct cpufreq_policy <cpufreq_policy>`
.. |intel_pstate| replace:: :doc:`intel_pstate <intel_pstate>`

=======================
CPU Performance Scaling
Expand Down Expand Up @@ -75,7 +76,7 @@ feedback registers, as that information is typically specific to the hardware
interface it comes from and may not be easily represented in an abstract,
platform-independent way. For this reason, ``CPUFreq`` allows scaling drivers
to bypass the governor layer and implement their own performance scaling
algorithms. That is done by the ``intel_pstate`` scaling driver.
algorithms. That is done by the |intel_pstate| scaling driver.


``CPUFreq`` Policy Objects
Expand Down Expand Up @@ -174,13 +175,13 @@ necessary to restart the scaling governor so that it can take the new online CPU
into account. That is achieved by invoking the governor's ``->stop`` and
``->start()`` callbacks, in this order, for the entire policy.

As mentioned before, the ``intel_pstate`` scaling driver bypasses the scaling
As mentioned before, the |intel_pstate| scaling driver bypasses the scaling
governor layer of ``CPUFreq`` and provides its own P-state selection algorithms.
Consequently, if ``intel_pstate`` is used, scaling governors are not attached to
Consequently, if |intel_pstate| is used, scaling governors are not attached to
new policy objects. Instead, the driver's ``->setpolicy()`` callback is invoked
to register per-CPU utilization update callbacks for each policy. These
callbacks are invoked by the CPU scheduler in the same way as for scaling
governors, but in the ``intel_pstate`` case they both determine the P-state to
governors, but in the |intel_pstate| case they both determine the P-state to
use and change the hardware configuration accordingly in one go from scheduler
context.

Expand Down Expand Up @@ -257,7 +258,7 @@ are the following:

``scaling_available_governors``
List of ``CPUFreq`` scaling governors present in the kernel that can
be attached to this policy or (if the ``intel_pstate`` scaling driver is
be attached to this policy or (if the |intel_pstate| scaling driver is
in use) list of scaling algorithms provided by the driver that can be
applied to this policy.

Expand All @@ -274,7 +275,7 @@ are the following:
the CPU is actually running at (due to hardware design and other
limitations).

Some scaling drivers (e.g. ``intel_pstate``) attempt to provide
Some scaling drivers (e.g. |intel_pstate|) attempt to provide
information more precisely reflecting the current CPU frequency through
this attribute, but that still may not be the exact current CPU
frequency as seen by the hardware at the moment.
Expand All @@ -284,13 +285,13 @@ are the following:

``scaling_governor``
The scaling governor currently attached to this policy or (if the
``intel_pstate`` scaling driver is in use) the scaling algorithm
|intel_pstate| scaling driver is in use) the scaling algorithm
provided by the driver that is currently applied to this policy.

This attribute is read-write and writing to it will cause a new scaling
governor to be attached to this policy or a new scaling algorithm
provided by the scaling driver to be applied to it (in the
``intel_pstate`` case), as indicated by the string written to this
|intel_pstate| case), as indicated by the string written to this
attribute (which must be one of the names listed by the
``scaling_available_governors`` attribute described above).

Expand Down Expand Up @@ -619,7 +620,7 @@ This file is located under :file:`/sys/devices/system/cpu/cpufreq/` and controls
the "boost" setting for the whole system. It is not present if the underlying
scaling driver does not support the frequency boost mechanism (or supports it,
but provides a driver-specific interface for controlling it, like
``intel_pstate``).
|intel_pstate|).

If the value in this file is 1, the frequency boost mechanism is enabled. This
means that either the hardware can be put into states in which it is able to
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1 change: 1 addition & 0 deletions Documentation/admin-guide/pm/index.rst
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ Power Management
:maxdepth: 2

cpufreq
intel_pstate

.. only:: subproject and html

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755 changes: 755 additions & 0 deletions Documentation/admin-guide/pm/intel_pstate.rst

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281 changes: 0 additions & 281 deletions Documentation/cpu-freq/intel-pstate.txt

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