Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...

[pandora-kernel.git] / drivers / cpufreq / cpufreq_ondemand.c

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index e741c33..1911d17 100644 (file)
--- 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");