cpufreq: Use transition_delay_us for legacy governors as well

The policy->transition_delay_us field is used only by the schedutil
governor currently, and this field describes how fast the driver wants
the cpufreq governor to change CPUs frequency. It should rather be a
common thing across all governors, as it doesn't have any schedutil
dependency here.

Create a new helper cpufreq_policy_transition_delay_us() to get the
transition delay across all governors.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 9bf97a366029f22b959a50d819d362b0f51bf5a4..c426d21822f7b6077678cc01c396bbfc3c95e27c 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -524,6 +524,21 @@ unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
 }
 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
 
+unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
+{
+       unsigned int latency;
+
+       if (policy->transition_delay_us)
+               return policy->transition_delay_us;
+
+       latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
+       if (latency)
+               return latency * LATENCY_MULTIPLIER;
+
+       return LATENCY_MULTIPLIER;
+}
+EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
+
 /*********************************************************************
  *                          SYSFS INTERFACE                          *
  *********************************************************************/

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 858081f9c3d73aa7d81e4b609191f9c419b7829c..eed069ecfd5ebf49a72a45e347f788c6cd13fe84 100644 (file)
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -389,7 +389,6 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
        struct dbs_governor *gov = dbs_governor_of(policy);
        struct dbs_data *dbs_data;
        struct policy_dbs_info *policy_dbs;
-       unsigned int latency;
        int ret = 0;
 
        /* State should be equivalent to EXIT */
@@ -428,13 +427,7 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
        if (ret)
                goto free_policy_dbs_info;
 
-       /* policy latency is in ns. Convert it to us first */
-       latency = policy->cpuinfo.transition_latency / 1000;
-       if (latency == 0)
-               latency = 1;
-
-       /* Bring kernel and HW constraints together */
-       dbs_data->sampling_rate = LATENCY_MULTIPLIER * latency;
+       dbs_data->sampling_rate = cpufreq_policy_transition_delay_us(policy);
 
        if (!have_governor_per_policy())
                gov->gdbs_data = dbs_data;

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 02aec384cab97dad6fe2fbaae50ab3beff0c47a3..aaadfc543f633514582d0405137c99493a698b7a 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -523,6 +523,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
                                   unsigned int relation);
 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
                                         unsigned int target_freq);
+unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy);
 int cpufreq_register_governor(struct cpufreq_governor *governor);
 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 29a397067ffa0f7c818990f3defe1a4bdd437708..89c4dd9777bbb379e869bb2fcaeccf2affc376d2 100644 (file)
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -528,16 +528,7 @@ static int sugov_init(struct cpufreq_policy *policy)
                goto stop_kthread;
        }
 
-       if (policy->transition_delay_us) {
-               tunables->rate_limit_us = policy->transition_delay_us;
-       } else {
-               unsigned int lat;
-
-               tunables->rate_limit_us = LATENCY_MULTIPLIER;
-               lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
-               if (lat)
-                       tunables->rate_limit_us *= lat;
-       }
+       tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
 
        policy->governor_data = sg_policy;
        sg_policy->tunables = tunables;