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SubjectRe: [PATCH] cpufreq: Refactor cpufreq_set_policy()
On 02/17/2014 06:36 AM, Rafael J. Wysocki wrote:
> 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>

Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>

Regards,
Srivatsa S. Bhat

> ---
> 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);
> }
>
> /**
>



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