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cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy

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A side effect of keeping intel_pstate sysfs limits in sync with cpufreq
is that the now sysfs limits can't enforced under performance policy.

For example, if the max_perf_pct is changed from 100 to 80, this will call
intel_pstate_set_policy(), which will change the max_perf to 100 again for
performance policy. Same issue happens, when no_turbo is set.

This change calculates max and min frequency using sysfs performance
limits in intel_pstate_verify_policy() and adjusts policy limits by
calling cpufreq_verify_within_limits().

Also, it causes the setting of performance limits to be skipped if
no_turbo is set.

Fixes: 111b8b3fe4 (cpufreq: intel_pstate: Always keep all limits settings in sync)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Srinivas Pandruvada 2017-01-18 10:48:22 -08:00 committed by Rafael J. Wysocki
parent e11b6293a8
commit 1443ebbacf
1 changed files with 13 additions and 1 deletions
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14
drivers/cpufreq/intel_pstate.c
View file

@ -1951,7 +1951,8 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
limits = &performance_limits;
perf_limits = limits;
}
if (policy->max >= policy->cpuinfo.max_freq) {
if (policy->max >= policy->cpuinfo.max_freq &&
!limits->no_turbo) {
pr_debug("set performance\n");
intel_pstate_set_performance_limits(perf_limits);
goto out;
@ -1993,6 +1994,17 @@ static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
policy->policy != CPUFREQ_POLICY_PERFORMANCE)
return -EINVAL;
/* When per-CPU limits are used, sysfs limits are not used */
if (!per_cpu_limits) {
unsigned int max_freq, min_freq;
max_freq = policy->cpuinfo.max_freq *
limits->max_sysfs_pct / 100;
min_freq = policy->cpuinfo.max_freq *
limits->min_sysfs_pct / 100;
cpufreq_verify_within_limits(policy, min_freq, max_freq);
}
return 0;
}