[PATCH] cpufreq: Refactor cpufreq_set_policy()

From: Rafael J. Wysocki
Date: Sun Feb 16 2014 - 19:51:36 EST


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

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@xxxxxxxxx>
---
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);
}

/**

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/