[PATCH v2] cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()

[Yue Hu <zbestahu@gmail.com>]

From: Yue Hu <huyue2@yulong.com>

In cpufreq_init_policy() we will check if there's last_governor for target
and setpolicy type. However last_governor is set only if has_target() is
true in cpufreq_offline(). That means find last_governor for setpolicy
type is pointless. Also new_policy.governor will not be used if ->setpolicy
callback is set in cpufreq_set_policy().

Moreover, there's duplicate ->setpolicy check in using default policy path.
Let's add a new helper function to avoid it. Also fix a little comment.

Signed-off-by: Yue Hu <huyue2@yulong.com>
---
v2: fix ->setplicy typo.

 drivers/cpufreq/cpufreq.c | 66 ++++++++++++++++++++++++++++-------------------
 1 file changed, 40 insertions(+), 26 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0322cce..b822a3e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -578,6 +578,20 @@ static struct cpufreq_governor *find_governor(const char *str_governor)
 	return NULL;
 }
 
+static int cpufreq_parse_static_governor(char *str_governor,
+					struct cpufreq_policy *policy)
+{
+	if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
+		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
+		return 0;
+	}
+	if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
+		policy->policy = CPUFREQ_POLICY_POWERSAVE;
+		return 0;
+	}
+	return -EINVAL;
+}
+
 /**
  * cpufreq_parse_governor - parse a governor string
  */
@@ -585,15 +599,7 @@ static int cpufreq_parse_governor(char *str_governor,
 				  struct cpufreq_policy *policy)
 {
 	if (cpufreq_driver->setpolicy) {
-		if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
-			policy->policy = CPUFREQ_POLICY_PERFORMANCE;
-			return 0;
-		}
-
-		if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
-			policy->policy = CPUFREQ_POLICY_POWERSAVE;
-			return 0;
-		}
+		return cpufreq_parse_static_governor(str_governor, policy);
 	} else {
 		struct cpufreq_governor *t;
 
@@ -1020,32 +1026,40 @@ __weak struct cpufreq_governor *cpufreq_default_governor(void)
 
 static int cpufreq_init_policy(struct cpufreq_policy *policy)
 {
-	struct cpufreq_governor *gov = NULL;
+	struct cpufreq_governor *gov = NULL, *def_gov = NULL;
 	struct cpufreq_policy new_policy;
 
 	memcpy(&new_policy, policy, sizeof(*policy));
 
-	/* Update governor of new_policy to the governor used before hotplug */
-	gov = find_governor(policy->last_governor);
-	if (gov) {
-		pr_debug("Restoring governor %s for cpu %d\n",
+	def_gov = cpufreq_default_governor();
+
+	if (has_target()) {
+		/*
+		 * Update governor of new_policy to the governor used before
+		 * hotplug
+		 */
+		gov = find_governor(policy->last_governor);
+		if (gov)
+			pr_debug("Restoring governor %s for cpu %d\n",
 				policy->governor->name, policy->cpu);
+		else {
+			if (!def_gov)
+				return -ENODATA;
+			gov = def_gov;
+		}
+		new_policy.governor = gov;
 	} else {
-		gov = cpufreq_default_governor();
-		if (!gov)
-			return -ENODATA;
-	}
-
-	new_policy.governor = gov;
-
-	/* Use the default policy if there is no last_policy. */
-	if (cpufreq_driver->setpolicy) {
+		/* Use the default policy if there is no last_policy. */
 		if (policy->last_policy)
 			new_policy.policy = policy->last_policy;
-		else
-			cpufreq_parse_governor(gov->name, &new_policy);
+		else {
+			if (!def_gov)
+				return -ENODATA;
+			cpufreq_parse_static_governor(def_gov->name,
+						      &new_policy);
+		}
 	}
-	/* set default policy */
+	/* Set new policy */
 	return cpufreq_set_policy(policy, &new_policy);
 }
 
-- 
1.9.1