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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-14 19:45:41 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-14 19:45:41 +0200
commit0b8417c14181595997091145342954332fa016cd (patch)
tree6a9c81a04ee42796e7b6dd4e212da5227d159d25 /Documentation/admin-guide
parentMerge tag 'platform-drivers-x86-v5.10-1' of git://git.kernel.org/pub/scm/linu... (diff)
parentMerge branches 'pm-avs' and 'powercap' (diff)
downloadlinux-0b8417c14181595997091145342954332fa016cd.tar.xz
linux-0b8417c14181595997091145342954332fa016cd.zip
Merge tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki: "These rework the collection of cpufreq statistics to allow it to take place if fast frequency switching is enabled in the governor, rework the frequency invariance handling in the cpufreq core and drivers, add new hardware support to a couple of cpufreq drivers, fix a number of assorted issues and clean up the code all over. Specifics: - Rework cpufreq statistics collection to allow it to take place when fast frequency switching is enabled in the governor (Viresh Kumar). - Make the cpufreq core set the frequency scale on behalf of the driver and update several cpufreq drivers accordingly (Ionela Voinescu, Valentin Schneider). - Add new hardware support to the STI and qcom cpufreq drivers and improve them (Alain Volmat, Manivannan Sadhasivam). - Fix multiple assorted issues in cpufreq drivers (Jon Hunter, Krzysztof Kozlowski, Matthias Kaehlcke, Pali Rohár, Stephan Gerhold, Viresh Kumar). - Fix several assorted issues in the operating performance points (OPP) framework (Stephan Gerhold, Viresh Kumar). - Allow devfreq drivers to fetch devfreq instances by DT enumeration instead of using explicit phandles and modify the devfreq core code to support driver-specific devfreq DT bindings (Leonard Crestez, Chanwoo Choi). - Improve initial hardware resetting in the tegra30 devfreq driver and clean up the tegra cpuidle driver (Dmitry Osipenko). - Update the cpuidle core to collect state entry rejection statistics and expose them via sysfs (Lina Iyer). - Improve the ACPI _CST code handling diagnostics (Chen Yu). - Update the PSCI cpuidle driver to allow the PM domain initialization to occur in the OSI mode as well as in the PC mode (Ulf Hansson). - Rework the generic power domains (genpd) core code to allow domain power off transition to be aborted in the absence of the "power off" domain callback (Ulf Hansson). - Fix two suspend-to-idle issues in the ACPI EC driver (Rafael Wysocki). - Fix the handling of timer_expires in the PM-runtime framework on 32-bit systems and the handling of device links in it (Grygorii Strashko, Xiang Chen). - Add IO requests batching support to the hibernate image saving and reading code and drop a bogus get_gendisk() from there (Xiaoyi Chen, Christoph Hellwig). - Allow PCIe ports to be put into the D3cold power state if they are power-manageable via ACPI (Lukas Wunner). - Add missing header file include to a power capping driver (Pujin Shi). - Clean up the qcom-cpr AVS driver a bit (Liu Shixin). - Kevin Hilman steps down as designated reviwer of adaptive voltage scaling (AVS) drivers (Kevin Hilman)" * tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (65 commits) cpufreq: stats: Fix string format specifier mismatch arm: disable frequency invariance for CONFIG_BL_SWITCHER cpufreq,arm,arm64: restructure definitions of arch_set_freq_scale() cpufreq: stats: Add memory barrier to store_reset() cpufreq: schedutil: Simplify sugov_fast_switch() ACPI: EC: PM: Drop ec_no_wakeup check from acpi_ec_dispatch_gpe() ACPI: EC: PM: Flush EC work unconditionally after wakeup PCI/ACPI: Whitelist hotplug ports for D3 if power managed by ACPI PM: hibernate: remove the bogus call to get_gendisk() in software_resume() cpufreq: Move traces and update to policy->cur to cpufreq core cpufreq: stats: Enable stats for fast-switch as well cpufreq: stats: Mark few conditionals with unlikely() cpufreq: stats: Remove locking cpufreq: stats: Defer stats update to cpufreq_stats_record_transition() PM: domains: Allow to abort power off when no ->power_off() callback PM: domains: Rename power state enums for genpd PM / devfreq: tegra30: Improve initial hardware resetting PM / devfreq: event: Change prototype of devfreq_event_get_edev_by_phandle function PM / devfreq: Change prototype of devfreq_get_devfreq_by_phandle function PM / devfreq: Add devfreq_get_devfreq_by_node function ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/pm/cpuidle.rst9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/admin-guide/pm/cpuidle.rst b/Documentation/admin-guide/pm/cpuidle.rst
index 6ebe163f9dfe..37940a0584ec 100644
--- a/Documentation/admin-guide/pm/cpuidle.rst
+++ b/Documentation/admin-guide/pm/cpuidle.rst
@@ -528,6 +528,10 @@ object corresponding to it, as follows:
Total number of times the hardware has been asked by the given CPU to
enter this idle state.
+``rejected``
+ Total number of times a request to enter this idle state on the given
+ CPU was rejected.
+
The :file:`desc` and :file:`name` files both contain strings. The difference
between them is that the name is expected to be more concise, while the
description may be longer and it may contain white space or special characters.
@@ -572,6 +576,11 @@ particular case. For these reasons, the only reliable way to find out how
much time has been spent by the hardware in different idle states supported by
it is to use idle state residency counters in the hardware, if available.
+Generally, an interrupt received when trying to enter an idle state causes the
+idle state entry request to be rejected, in which case the ``CPUIdle`` driver
+may return an error code to indicate that this was the case. The :file:`usage`
+and :file:`rejected` files report the number of times the given idle state
+was entered successfully or rejected, respectively.
.. _cpu-pm-qos: