linux-kernel - [PATCH 2/2] cpufreq: simplify cpufreq_set

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Message-Id: <20250819103940.342774-3-zhangzihuan@kylinos.cn>
Date: Tue, 19 Aug 2025 18:39:40 +0800
From: Zihuan Zhang <zhangzihuan@...inos.cn>
To: "rafael J . wysocki" <rafael@...nel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>
Cc: zhenglifeng <zhenglifeng1@...wei.com>,
	linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Zihuan Zhang <zhangzihuan@...inos.cn>
Subject: [PATCH 2/2] cpufreq: simplify cpufreq_set_policy() interface

The current cpufreq_set_policy() takes three arguments, including
new_pol. However, new_pol is only meaningful when a driver provides
the ->setpolicy callback. Most cpufreq drivers (e.g. ACPI) do not
implement this callback, so the extra parameter is unused.

Passing new_pol in such cases is unnecessary and may mislead readers
into thinking it has a functional effect, while in reality it is only
relevant for a very limited set of drivers.

Simplify the interface by removing the redundant argument and letting
drivers that implement ->setpolicy rely directly on
policy->policy. This reduces parameter passing overhead and makes the
API clearer.

Signed-off-by: Zihuan Zhang <zhangzihuan@...inos.cn>
---
 drivers/cpufreq/cpufreq.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index a067b5447fe8..ea4a5d3f786c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -85,8 +85,7 @@ static int cpufreq_init_governor(struct cpufreq_policy *policy);
 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
 static void cpufreq_governor_limits(struct cpufreq_policy *policy);
 static int cpufreq_set_policy(struct cpufreq_policy *policy,
-			      struct cpufreq_governor *new_gov,
-			      unsigned int new_pol);
+			      struct cpufreq_governor *new_gov);
 static bool cpufreq_boost_supported(void);
 static int cpufreq_boost_trigger_state(int state);
 
@@ -822,7 +821,8 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
 		if (!new_pol)
 			return -EINVAL;
 
-		ret = cpufreq_set_policy(policy, NULL, new_pol);
+		policy->policy = new_pol;
+		ret = cpufreq_set_policy(policy, NULL);
 	} else {
 		struct cpufreq_governor *new_gov;
 
@@ -830,8 +830,8 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
 		if (!new_gov)
 			return -EINVAL;
 
-		ret = cpufreq_set_policy(policy, new_gov,
-					 CPUFREQ_POLICY_UNKNOWN);
+		policy->policy = CPUFREQ_POLICY_UNKNOWN;
+		ret = cpufreq_set_policy(policy, new_gov);
 
 		module_put(new_gov->owner);
 	}
@@ -1154,7 +1154,8 @@ static int cpufreq_init_policy(struct cpufreq_policy *policy)
 			return -ENODATA;
 	}
 
-	ret = cpufreq_set_policy(policy, gov, pol);
+	policy->policy = pol;
+	ret = cpufreq_set_policy(policy, gov);
 	if (gov)
 		module_put(gov->owner);
 
@@ -1190,7 +1191,7 @@ void refresh_frequency_limits(struct cpufreq_policy *policy)
 	if (!policy_is_inactive(policy)) {
 		pr_debug("updating policy for CPU %u\n", policy->cpu);
 
-		cpufreq_set_policy(policy, policy->governor, policy->policy);
+		cpufreq_set_policy(policy, policy->governor);
 	}
 }
 EXPORT_SYMBOL(refresh_frequency_limits);
@@ -2610,7 +2611,6 @@ static void cpufreq_update_pressure(struct cpufreq_policy *policy)
  * cpufreq_set_policy - Modify cpufreq policy parameters.
  * @policy: Policy object to modify.
  * @new_gov: Policy governor pointer.
- * @new_pol: Policy value (for drivers with built-in governors).
  *
  * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
  * limits to be set for the policy, update @policy with the verified limits
@@ -2622,8 +2622,7 @@ static void cpufreq_update_pressure(struct cpufreq_policy *policy)
  * The cpuinfo part of @policy is not updated by this function.
  */
 static int cpufreq_set_policy(struct cpufreq_policy *policy,
-			      struct cpufreq_governor *new_gov,
-			      unsigned int new_pol)
+			      struct cpufreq_governor *new_gov)
 {
 	struct cpufreq_policy_data new_data;
 	struct cpufreq_governor *old_gov;
@@ -2676,7 +2675,6 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
 		 policy->min, policy->max);
 
 	if (cpufreq_driver->setpolicy) {
-		policy->policy = new_pol;
 		pr_debug("setting range\n");
 		return cpufreq_driver->setpolicy(policy);
 	}
-- 
2.25.1