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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM list <linux-pm@vger.kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Subject: [PATCH] cpufreq: Refactor cpufreq_set_policy()
Date: Mon, 17 Feb 2014 02:06:15 +0100	[thread overview]
Message-ID: <3582112.BRVGbkstFm@vostro.rjw.lan> (raw)

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reduce the rampant usage of goto and the indentation level in
cpufreq_set_policy() to improve the readability of that code.

No functional changes should result from that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpufreq/cpufreq.c |  102 ++++++++++++++++++++--------------------------
 1 file changed, 45 insertions(+), 57 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -2018,22 +2018,21 @@ EXPORT_SYMBOL(cpufreq_get_policy);
 static int cpufreq_set_policy(struct cpufreq_policy *policy,
 				struct cpufreq_policy *new_policy)
 {
-	int ret = 0, failed = 1;
+	struct cpufreq_governor *old_gov;
+	int ret;
 
 	pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu,
 		new_policy->min, new_policy->max);
 
 	memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
 
-	if (new_policy->min > policy->max || new_policy->max < policy->min) {
-		ret = -EINVAL;
-		goto error_out;
-	}
+	if (new_policy->min > policy->max || new_policy->max < policy->min)
+		return -EINVAL;
 
 	/* verify the cpu speed can be set within this limit */
 	ret = cpufreq_driver->verify(new_policy);
 	if (ret)
-		goto error_out;
+		return ret;
 
 	/* adjust if necessary - all reasons */
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
@@ -2049,7 +2048,7 @@ static int cpufreq_set_policy(struct cpu
 	 */
 	ret = cpufreq_driver->verify(new_policy);
 	if (ret)
-		goto error_out;
+		return ret;
 
 	/* notification of the new policy */
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
@@ -2064,58 +2063,47 @@ static int cpufreq_set_policy(struct cpu
 	if (cpufreq_driver->setpolicy) {
 		policy->policy = new_policy->policy;
 		pr_debug("setting range\n");
-		ret = cpufreq_driver->setpolicy(new_policy);
-	} else {
-		if (new_policy->governor != policy->governor) {
-			/* save old, working values */
-			struct cpufreq_governor *old_gov = policy->governor;
-
-			pr_debug("governor switch\n");
-
-			/* end old governor */
-			if (policy->governor) {
-				__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
-				up_write(&policy->rwsem);
-				__cpufreq_governor(policy,
-						CPUFREQ_GOV_POLICY_EXIT);
-				down_write(&policy->rwsem);
-			}
-
-			/* start new governor */
-			policy->governor = new_policy->governor;
-			if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {
-				if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) {
-					failed = 0;
-				} else {
-					up_write(&policy->rwsem);
-					__cpufreq_governor(policy,
-							CPUFREQ_GOV_POLICY_EXIT);
-					down_write(&policy->rwsem);
-				}
-			}
-
-			if (failed) {
-				/* new governor failed, so re-start old one */
-				pr_debug("starting governor %s failed\n",
-							policy->governor->name);
-				if (old_gov) {
-					policy->governor = old_gov;
-					__cpufreq_governor(policy,
-							CPUFREQ_GOV_POLICY_INIT);
-					__cpufreq_governor(policy,
-							   CPUFREQ_GOV_START);
-				}
-				ret = -EINVAL;
-				goto error_out;
-			}
-			/* might be a policy change, too, so fall through */
-		}
-		pr_debug("governor: change or update limits\n");
-		ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+		return cpufreq_driver->setpolicy(new_policy);
 	}
+	if (new_policy->governor == policy->governor)
+		goto out;
+
+	pr_debug("governor switch\n");
+
+	/* save old, working values */
+	old_gov = policy->governor;
+	/* end old governor */
+	if (old_gov) {
+		__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+		up_write(&policy->rwsem);
+		__cpufreq_governor(policy,CPUFREQ_GOV_POLICY_EXIT);
+		down_write(&policy->rwsem);
+	}
+
+	/* start new governor */
+	policy->governor = new_policy->governor;
+	if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {
+		if (!__cpufreq_governor(policy, CPUFREQ_GOV_START))
+			goto out;
+
+		up_write(&policy->rwsem);
+		__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+		down_write(&policy->rwsem);
+	}
+
+	/* new governor failed, so re-start old one */
+	pr_debug("starting governor %s failed\n", policy->governor->name);
+	if (old_gov) {
+		policy->governor = old_gov;
+		__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);
+		__cpufreq_governor(policy, CPUFREQ_GOV_START);
+	}
+
+	return -EINVAL;
 
-error_out:
-	return ret;
+ out:
+	pr_debug("governor: change or update limits\n");
+	return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
 }
 
 /**


             reply	other threads:[~2014-02-17  0:51 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-17  1:06 Rafael J. Wysocki [this message]
2014-02-17  5:21 ` Viresh Kumar
2014-02-18  9:10 ` Srivatsa S. Bhat

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