1 files changed, 25 insertions, 43 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index e741c339df76..1911d1729353 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -32,6 +32,7 @@
 #define DEF_FREQUENCY_UP_THRESHOLD              (80)
 #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL       (3)
 #define MICRO_FREQUENCY_UP_THRESHOLD            (95)
+#define MICRO_FREQUENCY_MIN_SAMPLE_RATE         (10000)
 #define MIN_FREQUENCY_UP_THRESHOLD              (11)
 #define MAX_FREQUENCY_UP_THRESHOLD              (100)
 
@@ -45,27 +46,12 @@
  * this governor will not work.
  * All times here are in uS.
  */
-static unsigned int def_sampling_rate;
 #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)
-/* Above MIN_SAMPLING_RATE will vanish with its sysfs file soon
- * Define the minimal settable sampling rate to the greater of:
- *   - "HW transition latency" * 100 (same as default sampling / 10)
- *   - MIN_STAT_SAMPLING_RATE
- * To avoid that userspace shoots itself.
-*/
-static unsigned int minimum_sampling_rate(void)
-{
-        return max(def_sampling_rate / 10, MIN_STAT_SAMPLING_RATE);
-}
 
-/* This will also vanish soon with removing sampling_rate_max */
-#define MAX_SAMPLING_RATE                       (500 * def_sampling_rate)
+static unsigned int min_sampling_rate;
+
 #define LATENCY_MULTIPLIER                      (1000)
+#define MIN_LATENCY_MULTIPLIER                  (100)
 #define TRANSITION_LATENCY_LIMIT                (10 * 1000 * 1000)
 
 static void do_dbs_timer(struct work_struct *work);
@@ -219,28 +205,14 @@ static void ondemand_powersave_bias_init(void)
 /************************** sysfs interface ************************/
 static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
 {
-        static int print_once;
-
-        if (!print_once) {
-                printk(KERN_INFO "CPUFREQ: ondemand sampling_rate_max "
-                       "sysfs file is deprecated - used by: %s\n",
-                       current->comm);
-                print_once = 1;
-        }
-        return sprintf(buf, "%u\n", MAX_SAMPLING_RATE);
+        printk_once(KERN_INFO "CPUFREQ: ondemand sampling_rate_max "
+               "sysfs file is deprecated - used by: %s\n", current->comm);
+        return sprintf(buf, "%u\n", -1U);
 }
 
 static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
 {
-        static int print_once;
-
-        if (!print_once) {
-                printk(KERN_INFO "CPUFREQ: ondemand sampling_rate_min "
-                       "sysfs file is deprecated - used by: %s\n",
-                       current->comm);
-                print_once = 1;
-        }
-        return sprintf(buf, "%u\n", MIN_SAMPLING_RATE);
+        return sprintf(buf, "%u\n", min_sampling_rate);
 }
 
 #define define_one_ro(_name)            \
@@ -274,7 +246,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
                 mutex_unlock(&dbs_mutex);
                 return -EINVAL;
         }
-        dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate());
+        dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
         mutex_unlock(&dbs_mutex);
 
         return count;
@@ -619,12 +591,12 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                         latency = policy->cpuinfo.transition_latency / 1000;
                         if (latency == 0)
                                 latency = 1;
-
-                        def_sampling_rate =
-                                max(latency * LATENCY_MULTIPLIER,
-                                    MIN_STAT_SAMPLING_RATE);
-
-                        dbs_tuners_ins.sampling_rate = def_sampling_rate;
+                        /* Bring kernel and HW constraints together */
+                        min_sampling_rate = max(min_sampling_rate,
+                                        MIN_LATENCY_MULTIPLIER * latency);
+                        dbs_tuners_ins.sampling_rate =
+                                max(min_sampling_rate,
+                                    latency * LATENCY_MULTIPLIER);
                 }
                 dbs_timer_init(this_dbs_info);
 
@@ -678,6 +650,16 @@ static int __init cpufreq_gov_dbs_init(void)
                 dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
                 dbs_tuners_ins.down_differential =
                                         MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
+                /*
+                 * In no_hz/micro accounting case we set the minimum frequency
+                 * not depending on HZ, but fixed (very low). The deferred
+                 * timer might skip some samples if idle/sleeping as needed.
+                */
+                min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
+        } else {
+                /* For correct statistics, we need 10 ticks for each measure */
+                min_sampling_rate =
+                        MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
         }
 
         kondemand_wq = create_workqueue("kondemand");