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2020-07-02cpufreq: Specify default governor on command lineQuentin Perret
Currently, the only way to specify the default CPUfreq governor is via Kconfig options, which suits users who can build the kernel themselves perfectly. However, for those who use a distro-like kernel (such as Android, with the Generic Kernel Image project), the only way to use a non-default governor is to boot to userspace, and to then switch using the sysfs interface. Being able to specify the default governor on the command line, like is the case for cpuidle, would allow those users to specify their governor of choice earlier on, and to simplify the userspace boot procedure slighlty. To support this use-case, add a kernel command line parameter allowing the default governor for CPUfreq to be specified, which takes precedence over the built-in default. This implementation has one notable limitation: the default governor must be registered before the driver. This is solved for builtin governors and drivers using appropriate *_initcall() functions. And in the modular case, this must be reflected as a constraint on the module loading order. Signed-off-by: Quentin Perret <qperret@google.com> [ Viresh: Converted 'default_governor' to a string and parsing it only at initcall level, and several updates to cpufreq_init_policy(). ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-08Documentation: PM: Unify copyright noticesRafael J. Wysocki
Unify copyright notices in the .rst files under Documentation/driver-api/pm and Documentation/admin-quide/pm. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-04-08Documentation: PM: Add SPDX license tags to multiple filesRafael J. Wysocki
Add SPDX license tags to .rst files under Documentation/driver-api/pm and Documentation/admin-quide/pm. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-04-08cpufreq: intel_pstate: Documentation: Add references sectionsRafael J. Wysocki
Add separate refereces sections to the cpufreq.rst and intel_pstate.rst documents under admin-quide/pm and list the references to external documentation in there. Update the ACPI specification URL while at it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-11-07Documentation: cpufreq: Correct a typoZhao Wei Liew
Fix a typo in the admin-guide documentation for cpufreq. Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-09-04Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: (33 commits) cpufreq: imx6q: Fix imx6sx low frequency support cpufreq: speedstep-lib: make several arrays static, makes code smaller cpufreq: ti: Fix 'of_node_put' being called twice in error handling path cpufreq: dt-platdev: Drop few entries from whitelist cpufreq: dt-platdev: Automatically create cpufreq device with OPP v2 ARM: ux500: don't select CPUFREQ_DT cpufreq: Convert to using %pOF instead of full_name cpufreq: Cap the default transition delay value to 10 ms cpufreq: dbx500: Delete obsolete driver mfd: db8500-prcmu: Get rid of cpufreq dependency cpufreq: enable the DT cpufreq driver on the Ux500 cpufreq: Loongson2: constify platform_device_id cpufreq: dt: Add r8a7796 support to to use generic cpufreq driver cpufreq: remove setting of policy->cpu in policy->cpus during init cpufreq: mediatek: add support of cpufreq to MT7622 SoC cpufreq: mediatek: add cleanups with the more generic naming cpufreq: rcar: Add support for R8A7795 SoC cpufreq: dt: Add rk3328 compatible to use generic cpufreq driver cpufreq: s5pv210: add missing of_node_put() cpufreq: Allow dynamic switching with CPUFREQ_ETERNAL latency ...
2017-07-27cpufreq: docs: Add missing cpuinfo_cur_freq descriptionRafael J. Wysocki
Add a description of the cpuinfo_cur_freq policy attribute in sysfs to the cpufreq documentation under Documentation/admin-guide/pm/ as it is missing after commit 2a0e49279850 (cpufreq: User/admin documentation update and consolidation) that overlooked it. Fixes: 2a0e49279850 (cpufreq: User/admin documentation update and consolidation) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2017-07-22cpufreq: governor: Drop min_sampling_rateViresh Kumar
The cpufreq core and governors aren't supposed to set a limit on how fast we want to try changing the frequency. This is currently done for the legacy governors with help of min_sampling_rate. At worst, we may end up setting the sampling rate to a value lower than the rate at which frequency can be changed and then one of the CPUs in the policy will be only changing frequency for ever. But that is something for the user to decide and there is no need to have special handling for such cases in the core. Leave it for the user to figure out. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-29cpufreq: Update scaling_cur_freq documentationRafael J. Wysocki
Commit f8475cef9008 "x86: use common aperfmperf_khz_on_cpu() to calculate KHz using APERF/MPERF" modified the way the scaling_cur_freq cpufreq policy attribute in sysfs is handled on contemporary Intel-based x86 systems, so update the documentation to reflect that change. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-14cpufreq: intel_pstate: Document the current behavior and user interfaceRafael J. Wysocki
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>
2017-03-13cpufreq: User/admin documentation update and consolidationRafael J. Wysocki
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>