1 files changed, 12 insertions, 6 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c1fc9c62bb51..17741111246b 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -48,7 +48,10 @@
  * All times here are in uS.
  */
 static unsigned int                             def_sampling_rate;
-#define MIN_SAMPLING_RATE                       (def_sampling_rate / 2)
+#define MIN_SAMPLING_RATE_RATIO                 (2)
+/* for correct statistics, we need at least 10 ticks between each measure */
+#define MIN_STAT_SAMPLING_RATE                  (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
+#define MIN_SAMPLING_RATE                       (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
 #define MAX_SAMPLING_RATE                       (500 * def_sampling_rate)
 #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER    (1000)
 #define DEF_SAMPLING_DOWN_FACTOR                (1)
@@ -416,13 +419,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                 if (dbs_enable == 1) {
                         unsigned int latency;
                         /* policy latency is in nS. Convert it to uS first */
+                        latency = policy->cpuinfo.transition_latency / 1000;
+                        if (latency == 0)
+                                latency = 1;
 
-                        latency = policy->cpuinfo.transition_latency;
-                        if (latency < 1000)
-                                latency = 1000;
-
-                        def_sampling_rate = (latency / 1000) *
+                        def_sampling_rate = latency *
                                         DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
+
+                        if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
+                                def_sampling_rate = MIN_STAT_SAMPLING_RATE;
+
                         dbs_tuners_ins.sampling_rate = def_sampling_rate;
                         dbs_tuners_ins.ignore_nice = 0;