Merge tag 'pm+acpi-4.6-rc5' of git://git.kernel.org/pub/scm/linux/ker…

…nel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Two fixes for issues introduced recently, one for an intel_pstate
  driver problem uncovered by the recent switch over from using timers
  and the other one for a potential cpufreq core problem related to
  system suspend/resume.

  Specifics:

   - Fix an intel_pstate driver problem causing CPUs to get stuck in the
     highest P-state when completely idle uncovered by the recent switch
     over from using timers (Rafael Wysocki).

   - Avoid attempts to get the current CPU frequency when all devices
     (like I2C controllers that may be nedded for that purpose) have
     been suspended during system suspend/resume (Rafael Wysocki)"

* tag 'pm+acpi-4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set
  intel_pstate: Avoid getting stuck in high P-states when idle

drivers/cpufreq/cpufreq.c

@@ -1491,6 +1491,9 @@ static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy)
 {
 	unsigned int new_freq;
 
+	if (cpufreq_suspended)
+		return 0;
+
 	new_freq = cpufreq_driver->get(policy->cpu);
 	if (!new_freq)
 		return 0;

drivers/cpufreq/intel_pstate.c

@@ -1130,6 +1130,10 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
 		sample_ratio = div_fp(int_tofp(pid_params.sample_rate_ns),
 				      int_tofp(duration_ns));
 		core_busy = mul_fp(core_busy, sample_ratio);
+	} else {
+		sample_ratio = div_fp(100 * cpu->sample.mperf, cpu->sample.tsc);
+		if (sample_ratio < int_tofp(1))
+			core_busy = 0;
 	}
 
 	cpu->sample.busy_scaled = core_busy;