linux-stable.git/include/linux/cpufreq.h, branch v5.15.208 Linux kernel stable tree cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay 2025-10-29T13:03:07+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2025-10-18T16:55:09+00:00 a510364e8cac08c0d37c368a7dd94ee406530d37 [ Upstream commit f965d111e68f4a993cc44d487d416e3d954eea11 ] If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a failure to retrieve the transition latency value from the platform firmware, the CPPC cpufreq driver will use that value (converted to microseconds) as the policy transition delay, but it is way too large for any practical use. Address this by making the driver use the cpufreq's default transition latency value (in microseconds) as the transition delay if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency(). Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us") Cc: 5.19+ <stable@vger.kernel.org> # 5.19 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> [ added CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS definition to include/linux/cpufreq.h ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f965d111e68f4a993cc44d487d416e3d954eea11 ]

If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a
failure to retrieve the transition latency value from the platform
firmware, the CPPC cpufreq driver will use that value (converted to
microseconds) as the policy transition delay, but it is way too large
for any practical use.

Address this by making the driver use the cpufreq's default
transition latency value (in microseconds) as the transition delay
if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency().

Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us")
Cc: 5.19+ <stable@vger.kernel.org> # 5.19
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
[ added CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS definition to include/linux/cpufreq.h ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: Move to_gov_attr_set() to cpufreq.h 2023-02-01T07:27:29+00:00 Kevin Hao haokexin@gmail.com 2022-01-23T12:45:06+00:00 7c513ced0decc48b1c2c69aca6480bcc2afe11c8 commit ae26508651272695a3ab353f75ab9a8daf3da324 upstream. So it can be reused by other codes. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ae26508651272695a3ab353f75ab9a8daf3da324 upstream.

So it can be reused by other codes.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: Fix parameter in parse_perf_domain() 2021-11-18T18:16:45+00:00 Hector.Yuan hector.yuan@mediatek.com 2021-10-04T14:42:33+00:00 8853e04ea61d4296b09347f361e3b3fd8f859b7f [ Upstream commit 4a08e3271c55f8b5d56906a8aa5bd041911cf897 ] Pass cpu to parse_perf_domain() instead of pcpu. Fixes: 8486a32dd484 ("cpufreq: Add of_perf_domain_get_sharing_cpumask") Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com> [ Viresh: Massaged changelog ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4a08e3271c55f8b5d56906a8aa5bd041911cf897 ]

Pass cpu to parse_perf_domain() instead of pcpu.

Fixes: 8486a32dd484 ("cpufreq: Add of_perf_domain_get_sharing_cpumask")
Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com>
[ Viresh: Massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge branch 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm 2021-09-07T13:42:10+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2021-09-07T13:42:10+00:00 27de8d597020755b6bdeca7036463ca6d0b4c295 Pull more ARM cpufreq changes for v5.15-rc1 from Viresh Kumar: "This adds a new cpufreq driver for Mediatek, which had been going through reviews since last one year." * 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm: cpufreq: mediatek-hw: Add support for CPUFREQ HW cpufreq: Add of_perf_domain_get_sharing_cpumask dt-bindings: cpufreq: add bindings for MediaTek cpufreq HW 
Pull more ARM cpufreq changes for v5.15-rc1 from Viresh Kumar:

"This adds a new cpufreq driver for Mediatek, which had been going
 through reviews since last one year."

* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  cpufreq: mediatek-hw: Add support for CPUFREQ HW
  cpufreq: Add of_perf_domain_get_sharing_cpumask
  dt-bindings: cpufreq: add bindings for MediaTek cpufreq HW
cpufreq: Add of_perf_domain_get_sharing_cpumask 2021-09-06T09:44:35+00:00 Hector.Yuan hector.yuan@mediatek.com 2021-09-03T08:39:23+00:00 8486a32dd484a7d7ec25295c7439094608f54915 Add of_perf_domain_get_sharing_cpumask function to group cpu to specific performance domain. Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com> [ Viresh: create separate routine parse_perf_domain() and always set the cpumask. ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> 
Add of_perf_domain_get_sharing_cpumask function to group cpu
to specific performance domain.

Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com>
[ Viresh: create separate routine parse_perf_domain() and always set the
	  cpumask. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: Remove ready() callback 2021-09-02T16:04:17+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-09-01T09:11:57+00:00 4bf8e582119ed9767f907abb6dc62ef9dddf10df This isn't used anymore, get rid of it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
This isn't used anymore, get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Add callback to register with energy model 2021-08-12T04:24:07+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-08-10T06:34:33+00:00 c17495b01b72b53bd290f442d39b060e015c7aea Many cpufreq drivers register with the energy model for each policy and do exactly the same thing. Follow the footsteps of thermal-cooling, to get it done from the cpufreq core itself. Provide a new callback, which will be called, if present, by the cpufreq core at the right moment (more on that in the code's comment). Also provide a generic implementation that uses dev_pm_opp_of_register_em(). This also allows us to register with the EM at a later point of time, compared to ->init(), from where the EM core can access cpufreq policy directly using cpufreq_cpu_get() type of helpers and perform other work, like marking few frequencies inefficient, this will be done separately. Reviewed-by: Quentin Perret <qperret@google.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> 
Many cpufreq drivers register with the energy model for each policy and
do exactly the same thing. Follow the footsteps of thermal-cooling, to
get it done from the cpufreq core itself.

Provide a new callback, which will be called, if present, by the cpufreq
core at the right moment (more on that in the code's comment). Also
provide a generic implementation that uses dev_pm_opp_of_register_em().

This also allows us to register with the EM at a later point of time,
compared to ->init(), from where the EM core can access cpufreq policy
directly using cpufreq_cpu_get() type of helpers and perform other work,
like marking few frequencies inefficient, this will be done separately.

Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: Remove ->resolve_freq() 2021-06-30T17:45:42+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-06-29T06:27:08+00:00 b3beca76181681fce9cf72f37d19c3030e3353c0 Commit e3c062360870 ("cpufreq: add cpufreq_driver_resolve_freq()") introduced this callback, back in 2016, for drivers that provide the ->target() callback. The kernel hasn't seen a single user of it in the past 5 years and it is not likely to be used any time soon. Remove it for now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Commit e3c062360870 ("cpufreq: add cpufreq_driver_resolve_freq()")
introduced this callback, back in 2016, for drivers that provide the
->target() callback.

The kernel hasn't seen a single user of it in the past 5 years and
it is not likely to be used any time soon.

Remove it for now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Remove the ->stop_cpu() driver callback 2021-06-30T16:54:11+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-06-23T04:24:42+00:00 3e0f897fd92662f0ff21ca1759d724a9ad574858 Now that all users of ->stop_cpu() have been migrated to using other callbacks, drop it from the core. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Minor edits in the subject and changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Now that all users of ->stop_cpu() have been migrated to using other
callbacks, drop it from the core.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Minor edits in the subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Remove unused flag CPUFREQ_PM_NO_WARN 2021-02-04T18:25:47+00:00 Viresh Kumar viresh.kumar@linaro.org 2021-02-02T05:41:55+00:00 2f0531869fd22182e769b10dd6cf151861ede791 This flag is set by one of the drivers but it isn't used in the code otherwise. Remove the unused flag and update the driver. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
This flag is set by one of the drivers but it isn't used in the code
otherwise. Remove the unused flag and update the driver.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>