[PATCH 1/2] cpufreq: add __find_governor helper and clean up some error handling

[Jeremy Fitzhardinge <jeremy@goop.org>]

Adds a __find_governor() helper function to look up a governor by
name.  Also restructures some error handling to conform to the
"single-exit" model which is generally preferred for kernel code.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>

---
drivers/cpufreq/cpufreq.c |   59 ++++++++++++++++++++++++++-------------------
1 file changed, 35 insertions(+), 24 deletions(-)


diff -r 46ca283d1fe1 drivers/cpufreq/cpufreq.c
--- a/drivers/cpufreq/cpufreq.c	Mon Jul 03 13:37:39 2006 -0700
+++ b/drivers/cpufreq/cpufreq.c	Wed Jul 05 22:26:52 2006 -0700
@@ -284,39 +284,52 @@ EXPORT_SYMBOL_GPL(cpufreq_notify_transit
 *                          SYSFS INTERFACE                          *
 *********************************************************************/

+static struct cpufreq_governor *__find_governor(const char *str_governor)
+{
+	struct cpufreq_governor *t;
+	
+	list_for_each_entry(t, &cpufreq_governor_list, governor_list)
+		if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN))
+			return t;
+
+	return NULL;
+}
+
/**
 * cpufreq_parse_governor - parse a governor string
 */
static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
				struct cpufreq_governor **governor)
{
+	int err = -EINVAL;
+
	if (!cpufreq_driver)
-		return -EINVAL;
+		goto out;
+
	if (cpufreq_driver->setpolicy) {
		if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
			*policy = CPUFREQ_POLICY_PERFORMANCE;
-			return 0;
+			err = 0;
		} else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
			*policy = CPUFREQ_POLICY_POWERSAVE;
-			return 0;
+			err = 0;
		}
-		return -EINVAL;
-	} else {
+	} else if (cpufreq_driver->target) {
		struct cpufreq_governor *t;
+
		mutex_lock(&cpufreq_governor_mutex);
-		if (!cpufreq_driver || !cpufreq_driver->target)
-			goto out;
-		list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
-			if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
-				*governor = t;
-				mutex_unlock(&cpufreq_governor_mutex);
-				return 0;
-			}
+
+		t = __find_governor(str_governor);
+
+		if (t != NULL) {
+			*governor = t;
+			err = 0;
		}
-out:
+
		mutex_unlock(&cpufreq_governor_mutex);
	}
-	return -EINVAL;
+  out:
+	return err;
}


@@ -1273,23 +1286,21 @@ EXPORT_SYMBOL_GPL(cpufreq_governor);

int cpufreq_register_governor(struct cpufreq_governor *governor)
{
-	struct cpufreq_governor *t;
+	int err;

	if (!governor)
		return -EINVAL;

	mutex_lock(&cpufreq_governor_mutex);

-	list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
-		if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
-			mutex_unlock(&cpufreq_governor_mutex);
-			return -EBUSY;
-		}
-	}
-	list_add(&governor->governor_list, &cpufreq_governor_list);
+	err = -EBUSY;
+	if (__find_governor(governor->name) == NULL) {
+		err = 0;
+		list_add(&governor->governor_list, &cpufreq_governor_list);
+	}

	mutex_unlock(&cpufreq_governor_mutex);
-	return 0;
+	return err;
}
EXPORT_SYMBOL_GPL(cpufreq_register_governor);


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