cpufreq: intel_pstate: Avoid triggering cpu_frequency tracepoint unnecessarily

In the passive mode the cpu_frequency trace event is already
triggered by the cpufreq core or by scaling governors, so
intel_pstate should not trigger it once again for the same
P-state updates.

In addition to that, the frequency returned by
intel_cpufreq_fast_switch() and passed via freqs.new from
intel_cpufreq_target() to cpufreq_freq_transition_end() should
reflect the P-state actually set, so make that happen.

Fixes: 001c76f05b01 (cpufreq: intel_pstate: Generic governors support)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 04b2aa16227637b0f70ba2c80a81e2c290d7e763..5e066b332598743202466637283c6a5a83b9f365 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1879,13 +1879,11 @@ static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate)
 
        intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
        pstate = clamp_t(int, pstate, min_perf, max_perf);
-       trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
        return pstate;
 }
 
 static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)
 {
-       pstate = intel_pstate_prepare_request(cpu, pstate);
        if (pstate == cpu->pstate.current_pstate)
                return;
 
@@ -1905,6 +1903,8 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 
        update_turbo_state();
 
+       target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
+       trace_cpu_frequency(target_pstate * cpu->pstate.scaling, cpu->cpu);
        intel_pstate_update_pstate(cpu, target_pstate);
 
        sample = &cpu->sample;
@@ -2365,6 +2365,7 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy,
                wrmsrl_on_cpu(policy->cpu, MSR_IA32_PERF_CTL,
                              pstate_funcs.get_val(cpu, target_pstate));
        }
+       freqs.new = target_pstate * cpu->pstate.scaling;
        cpufreq_freq_transition_end(policy, &freqs, false);
 
        return 0;
@@ -2378,8 +2379,9 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy,
 
        target_freq = intel_cpufreq_turbo_update(cpu, policy, target_freq);
        target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling);
+       target_pstate = intel_pstate_prepare_request(cpu, target_pstate);
        intel_pstate_update_pstate(cpu, target_pstate);
-       return target_freq;
+       return target_pstate * cpu->pstate.scaling;
 }
 
 static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)