Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq

3 files changed, 21 insertions, 12 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 6c6121b85a54..25acf478c9e8 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -593,12 +593,11 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
                 goto module_out;
         }
 
-        policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+        policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
         if (!policy) {
                 ret = -ENOMEM;
                 goto nomem_out;
         }
-        memset(policy, 0, sizeof(struct cpufreq_policy));
 
         policy->cpu = cpu;
         policy->cpus = cpumask_of_cpu(cpu);
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;
 
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 3597f25d5efa..0bddb8e694d9 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -193,11 +193,15 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
         unsigned int cpu = policy->cpu;
         if (cpufreq_stats_table[cpu])
                 return -EBUSY;
-        if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
+        if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
                 return -ENOMEM;
-        memset(stat, 0, sizeof (struct cpufreq_stats));
 
         data = cpufreq_cpu_get(cpu);
+        if (data == NULL) {
+                ret = -EINVAL;
+                goto error_get_fail;
+        }
+
         if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
                 goto error_out;
 
@@ -217,12 +221,11 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
         alloc_size += count * count * sizeof(int);
 #endif
         stat->max_state = count;
-        stat->time_in_state = kmalloc(alloc_size, GFP_KERNEL);
+        stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
         if (!stat->time_in_state) {
                 ret = -ENOMEM;
                 goto error_out;
         }
-        memset(stat->time_in_state, 0, alloc_size);
         stat->freq_table = (unsigned int *)(stat->time_in_state + count);
 
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
@@ -245,6 +248,7 @@ cpufreq_stats_create_table (struct cpufreq_policy *policy,
         return 0;
 error_out:
         cpufreq_cpu_put(data);
+error_get_fail:
         kfree(stat);
         cpufreq_stats_table[cpu] = NULL;
         return ret;