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Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c1fc9c62bb5..17741111246 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -48,7 +48,10 @@
48 * All times here are in uS. 48 * All times here are in uS.
49 */ 49 */
50static unsigned int def_sampling_rate; 50static unsigned int def_sampling_rate;
51#define MIN_SAMPLING_RATE (def_sampling_rate / 2) 51#define MIN_SAMPLING_RATE_RATIO (2)
52/* for correct statistics, we need at least 10 ticks between each measure */
53#define MIN_STAT_SAMPLING_RATE (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
54#define MIN_SAMPLING_RATE (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
52#define MAX_SAMPLING_RATE (500 * def_sampling_rate) 55#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
53#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) 56#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000)
54#define DEF_SAMPLING_DOWN_FACTOR (1) 57#define DEF_SAMPLING_DOWN_FACTOR (1)
@@ -416,13 +419,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
416 if (dbs_enable == 1) { 419 if (dbs_enable == 1) {
417 unsigned int latency; 420 unsigned int latency;
418 /* policy latency is in nS. Convert it to uS first */ 421 /* policy latency is in nS. Convert it to uS first */
422 latency = policy->cpuinfo.transition_latency / 1000;
423 if (latency == 0)
424 latency = 1;
419 425
420 latency = policy->cpuinfo.transition_latency; 426 def_sampling_rate = latency *
421 if (latency < 1000)
422 latency = 1000;
423
424 def_sampling_rate = (latency / 1000) *
425 DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; 427 DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
428
429 if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
430 def_sampling_rate = MIN_STAT_SAMPLING_RATE;
431
426 dbs_tuners_ins.sampling_rate = def_sampling_rate; 432 dbs_tuners_ins.sampling_rate = def_sampling_rate;
427 dbs_tuners_ins.ignore_nice = 0; 433 dbs_tuners_ins.ignore_nice = 0;
428 434