1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 8532bb79e5fc..e794527e4925 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -96,15 +96,25 @@ static struct dbs_tuners {
 
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
 {
-        cputime64_t retval;
+        cputime64_t idle_time;
+        cputime64_t cur_jiffies;
+        cputime64_t busy_time;
 
-        retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
-                        kstat_cpu(cpu).cpustat.iowait);
+        cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
+        busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
+                        kstat_cpu(cpu).cpustat.system);
 
-        if (dbs_tuners_ins.ignore_nice)
-                retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
+        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
+        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
+        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
 
-        return retval;
+        if (!dbs_tuners_ins.ignore_nice) {
+                busy_time = cputime64_add(busy_time,
+                                kstat_cpu(cpu).cpustat.nice);
+        }
+
+        idle_time = cputime64_sub(cur_jiffies, busy_time);
+        return idle_time;
 }
 
 /*
@@ -325,7 +335,7 @@ static struct attribute_group dbs_attr_group = {
 static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 {
         unsigned int idle_ticks, total_ticks;
-        unsigned int load;
+        unsigned int load = 0;
         cputime64_t cur_jiffies;
 
         struct cpufreq_policy *policy;
@@ -339,7 +349,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
         cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
         total_ticks = (unsigned int) cputime64_sub(cur_jiffies,
                         this_dbs_info->prev_cpu_wall);
-        this_dbs_info->prev_cpu_wall = cur_jiffies;
+        this_dbs_info->prev_cpu_wall = get_jiffies_64();
+
         if (!total_ticks)
                 return;
         /*
@@ -370,7 +381,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
                 if (tmp_idle_ticks < idle_ticks)
                         idle_ticks = tmp_idle_ticks;
         }
-        load = (100 * (total_ticks - idle_ticks)) / total_ticks;
+        if (likely(total_ticks > idle_ticks))
+                load = (100 * (total_ticks - idle_ticks)) / total_ticks;
 
         /* Check for frequency increase */
         if (load > dbs_tuners_ins.up_threshold) {