[CPUFREQ] Prevents un-necessary cpufreq changes if we are already at min/max

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 7d7244314ac9..6dc83808e590 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -333,6 +333,10 @@ static void dbs_check_cpu(int cpu)
                         usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
 
         if (idle_ticks < up_idle_ticks) {
+                /* if we are already at full speed then break out early */
+                if (policy->cur == policy->max)
+                        return;
+                
                 __cpufreq_driver_target(policy, policy->max, 
                         CPUFREQ_RELATION_H);
                 down_skip[cpu] = 0;
@@ -386,6 +390,10 @@ static void dbs_check_cpu(int cpu)
                         usecs_to_jiffies(freq_down_sampling_rate);
 
         if (idle_ticks > down_idle_ticks ) {
+                /* if we are already at the lowest speed then break out early */
+                if (policy->cur == policy->min)
+                        return;
+                
                 freq_down_step = (5 * policy->max) / 100;
 
                 /* max freq cannot be less than 100. But who knows.... */