From: Pierre Gondois <pierre.gondois@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Jie Zhan <zhanjie9@hisilicon.com>,
Lifeng Zheng <zhenglifeng1@huawei.com>,
Ionela Voinescu <ionela.voinescu@arm.com>,
Sumit Gupta <sumitg@nvidia.com>,
Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>,
Pierre Gondois <pierre.gondois@arm.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Huang Rui <ray.huang@amd.com>,
Mario Limonciello <mario.limonciello@amd.com>,
Perry Yuan <perry.yuan@amd.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Len Brown <lenb@kernel.org>,
Saravana Kannan <saravanak@kernel.org>,
linux-pm@vger.kernel.org, linux-doc@vger.kernel.org
Subject: [PATCH v2 3/4] cpufreq: Remove driver default policy->min/max init
Date: Mon, 11 May 2026 15:55:30 +0200 [thread overview]
Message-ID: <20260511135538.522653-4-pierre.gondois@arm.com> (raw)
In-Reply-To: <20260511135538.522653-1-pierre.gondois@arm.com>
Prior to [1], drivers were setting policy->min/max and
the value was used as a QoS constraint. After that change,
the values were only temporarily used: cpufreq_set_policy()
ultimately overriding them through:
cpufreq_policy_online()
\-cpufreq_init_policy()
\-cpufreq_set_policy()
\-/* Set policy->min/max */
This patch reinstate the initial behaviour. This will allow
drivers to request min/max QoS frequencies if desired.
For instance, the cppc driver advertises a lowest non-linear
frequency, which should be used as a min QoS value.
To avoid having drivers setting policy->min/max to default
values which are considered as QoS values (i.e. the reason
why [1] was introduced), remove the initialization of
policy->min/max in .init() callbacks wherever the
policy->min/max values are identical to the
policy->cpuinfo.min/max_freq.
Indeed, the previous patch ("cpufreq: Set default
policy->min/max values for all drivers") makes this initialization
redundant.
The only drivers where these values are different are:
- gx-suspmod.c (min)
- cppc-cpufreq.c (min)
- longrun.c
[1]
commit 521223d8b3ec ("cpufreq: Fix initialization of min and
max frequency QoS requests")
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
drivers/cpufreq/amd-pstate.c | 14 ++++++--------
drivers/cpufreq/cppc_cpufreq.c | 5 ++---
drivers/cpufreq/cpufreq-nforce2.c | 4 ++--
drivers/cpufreq/freq_table.c | 7 +++----
drivers/cpufreq/gx-suspmod.c | 2 +-
drivers/cpufreq/intel_pstate.c | 3 ---
drivers/cpufreq/pcc-cpufreq.c | 10 ++++------
drivers/cpufreq/pxa3xx-cpufreq.c | 5 ++---
drivers/cpufreq/sh-cpufreq.c | 6 ++----
drivers/cpufreq/virtual-cpufreq.c | 5 +----
10 files changed, 23 insertions(+), 38 deletions(-)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 453084c67327f..ecc3779e047d5 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1090,10 +1090,9 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
perf = READ_ONCE(cpudata->perf);
- policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
- cpudata->nominal_freq,
- perf.lowest_perf);
- policy->cpuinfo.max_freq = policy->max = cpudata->max_freq;
+ policy->cpuinfo.min_freq = perf_to_freq(perf, cpudata->nominal_freq,
+ perf.lowest_perf);
+ policy->cpuinfo.max_freq = cpudata->max_freq;
policy->driver_data = cpudata;
ret = amd_pstate_cppc_enable(policy);
@@ -1907,10 +1906,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
perf = READ_ONCE(cpudata->perf);
- policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
- cpudata->nominal_freq,
- perf.lowest_perf);
- policy->cpuinfo.max_freq = policy->max = cpudata->max_freq;
+ policy->cpuinfo.min_freq = perf_to_freq(perf, cpudata->nominal_freq,
+ perf.lowest_perf);
+ policy->cpuinfo.max_freq = cpudata->max_freq;
policy->driver_data = cpudata;
ret = amd_pstate_cppc_enable(policy);
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 7e7f9dfb7a24c..5abac50df7508 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -660,8 +660,6 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
* Section 8.4.7.1.1.5 of ACPI 6.1 spec)
*/
policy->min = cppc_perf_to_khz(caps, caps->lowest_nonlinear_perf);
- policy->max = cppc_perf_to_khz(caps, policy->boost_enabled ?
- caps->highest_perf : caps->nominal_perf);
/*
* Set cpuinfo.min_freq to Lowest to make the full range of performance
@@ -669,7 +667,8 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
* nonlinear perf
*/
policy->cpuinfo.min_freq = cppc_perf_to_khz(caps, caps->lowest_perf);
- policy->cpuinfo.max_freq = policy->max;
+ policy->cpuinfo.max_freq = cppc_perf_to_khz(caps, policy->boost_enabled ?
+ caps->highest_perf : caps->nominal_perf);
policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
policy->shared_type = cpu_data->shared_type;
diff --git a/drivers/cpufreq/cpufreq-nforce2.c b/drivers/cpufreq/cpufreq-nforce2.c
index fbbbe501cf2dc..831102522ad64 100644
--- a/drivers/cpufreq/cpufreq-nforce2.c
+++ b/drivers/cpufreq/cpufreq-nforce2.c
@@ -355,8 +355,8 @@ static int nforce2_cpu_init(struct cpufreq_policy *policy)
min_fsb = NFORCE2_MIN_FSB;
/* cpuinfo and default policy values */
- policy->min = policy->cpuinfo.min_freq = min_fsb * fid * 100;
- policy->max = policy->cpuinfo.max_freq = max_fsb * fid * 100;
+ policy->cpuinfo.min_freq = min_fsb * fid * 100;
+ policy->cpuinfo.max_freq = max_fsb * fid * 100;
return 0;
}
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 5b364d8da4f92..ea994647abc88 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -49,16 +49,15 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy)
max_freq = freq;
}
- policy->min = policy->cpuinfo.min_freq = min_freq;
- policy->max = max_freq;
+ policy->cpuinfo.min_freq = min_freq;
/*
* If the driver has set its own cpuinfo.max_freq above max_freq, leave
* it as is.
*/
if (policy->cpuinfo.max_freq < max_freq)
- policy->max = policy->cpuinfo.max_freq = max_freq;
+ policy->cpuinfo.max_freq = max_freq;
- if (policy->min == ~0)
+ if (min_freq == ~0)
return -EINVAL;
else
return 0;
diff --git a/drivers/cpufreq/gx-suspmod.c b/drivers/cpufreq/gx-suspmod.c
index d269a4f26f98e..d40c9e0bbb740 100644
--- a/drivers/cpufreq/gx-suspmod.c
+++ b/drivers/cpufreq/gx-suspmod.c
@@ -421,7 +421,7 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy)
policy->min = maxfreq / max_duration;
else
policy->min = maxfreq / POLICY_MIN_DIV;
- policy->max = maxfreq;
+
policy->cpuinfo.min_freq = maxfreq / max_duration;
policy->cpuinfo.max_freq = maxfreq;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1292da53e5fcb..68ccc6eb1ef30 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3049,9 +3049,6 @@ static int __intel_pstate_cpu_init(struct cpufreq_policy *policy)
policy->cpuinfo.max_freq = READ_ONCE(global.no_turbo) ?
cpu->pstate.max_freq : cpu->pstate.turbo_freq;
- policy->min = policy->cpuinfo.min_freq;
- policy->max = policy->cpuinfo.max_freq;
-
intel_pstate_init_acpi_perf_limits(policy);
policy->fast_switch_possible = true;
diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c
index ac2e90a65f0c4..0f185a13577f8 100644
--- a/drivers/cpufreq/pcc-cpufreq.c
+++ b/drivers/cpufreq/pcc-cpufreq.c
@@ -551,13 +551,11 @@ static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
goto out;
}
- policy->max = policy->cpuinfo.max_freq =
- ioread32(&pcch_hdr->nominal) * 1000;
- policy->min = policy->cpuinfo.min_freq =
- ioread32(&pcch_hdr->minimum_frequency) * 1000;
+ policy->cpuinfo.max_freq = ioread32(&pcch_hdr->nominal) * 1000;
+ policy->cpuinfo.min_freq = ioread32(&pcch_hdr->minimum_frequency) * 1000;
- pr_debug("init: policy->max is %d, policy->min is %d\n",
- policy->max, policy->min);
+ pr_debug("init: max_freq is %d, min_freq is %d\n",
+ policy->cpuinfo.max_freq, policy->cpuinfo.min_freq);
out:
return result;
}
diff --git a/drivers/cpufreq/pxa3xx-cpufreq.c b/drivers/cpufreq/pxa3xx-cpufreq.c
index 50ff3b6a69000..06b27cbc59d6a 100644
--- a/drivers/cpufreq/pxa3xx-cpufreq.c
+++ b/drivers/cpufreq/pxa3xx-cpufreq.c
@@ -185,9 +185,8 @@ static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
int ret = -EINVAL;
/* set default policy and cpuinfo */
- policy->min = policy->cpuinfo.min_freq = 104000;
- policy->max = policy->cpuinfo.max_freq =
- (cpu_is_pxa320()) ? 806000 : 624000;
+ policy->cpuinfo.min_freq = 104000;
+ policy->cpuinfo.max_freq = (cpu_is_pxa320()) ? 806000 : 624000;
policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
if (cpu_is_pxa300() || cpu_is_pxa310())
diff --git a/drivers/cpufreq/sh-cpufreq.c b/drivers/cpufreq/sh-cpufreq.c
index 642ddb9ea217e..3c99d7009cbe2 100644
--- a/drivers/cpufreq/sh-cpufreq.c
+++ b/drivers/cpufreq/sh-cpufreq.c
@@ -124,10 +124,8 @@ static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
dev_notice(dev, "no frequency table found, falling back "
"to rate rounding.\n");
- policy->min = policy->cpuinfo.min_freq =
- (clk_round_rate(cpuclk, 1) + 500) / 1000;
- policy->max = policy->cpuinfo.max_freq =
- (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
+ policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
+ policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
}
return 0;
diff --git a/drivers/cpufreq/virtual-cpufreq.c b/drivers/cpufreq/virtual-cpufreq.c
index 4159f31349b16..dc78b74409af4 100644
--- a/drivers/cpufreq/virtual-cpufreq.c
+++ b/drivers/cpufreq/virtual-cpufreq.c
@@ -164,10 +164,7 @@ static int virt_cpufreq_get_freq_info(struct cpufreq_policy *policy)
policy->cpuinfo.min_freq = 1;
policy->cpuinfo.max_freq = virt_cpufreq_get_perftbl_entry(policy->cpu, 0);
- policy->min = policy->cpuinfo.min_freq;
- policy->max = policy->cpuinfo.max_freq;
-
- policy->cur = policy->max;
+ policy->cur = policy->cpuinfo.max_freq;
return 0;
}
--
2.43.0
next prev parent reply other threads:[~2026-05-11 13:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-11 13:55 [PATCH v2 0/4] cpufreq: Set policy->min and max as real QoS constraints Pierre Gondois
2026-05-11 13:55 ` [PATCH v2 1/4] cpufreq: Extract cpufreq_policy_init_qos() function Pierre Gondois
2026-05-11 13:55 ` [PATCH v2 2/4] cpufreq: Set default policy->min/max values for all drivers Pierre Gondois
2026-05-11 13:55 ` Pierre Gondois [this message]
2026-05-11 13:55 ` [PATCH v2 4/4] cpufreq: Use policy->min/max init as QoS request Pierre Gondois
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