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cpufreq: intel_pstate: Fix intel_pstate_verify_policy() 

The code added to intel_pstate_verify_policy() by commit 1443ebbacf
(cpufreq: intel_pstate: Fix sysfs limits enforcement for performance
policy) should use perf_limits instead of limits, because otherwise
setting global limits via sysfs may affect policies inconsistently.

For example, in the sequence of shell commands below, the
scaling_min_freq attribute for policy1 and policy2 should be
affected in the same way, because scaling_governor is set in
the same way for both of them:

 # cat cpufreq/policy1/scaling_governor
 powersave
 # cat cpufreq/policy2/scaling_governor
 powersave
 # echo performance > cpufreq/policy0/scaling_governor
 # echo 94 > intel_pstate/min_perf_pct
 # cat cpufreq/policy0/scaling_min_freq
 2914000
 # cat cpufreq/policy1/scaling_min_freq
 2914000
 # cat cpufreq/policy2/scaling_min_freq
 800000

The are affected differently, because intel_pstate_verify_policy()
is invoked with limits set to &performance_limits (left behind by
policy0) for policy1 and with limits set to &powersave_limits (left
behind by policy1) for policy2.  Since perf_limits is set to the
set of limits matching the policy being updated, using it instead
of limits fixes the inconsistency.

Fixes: 1443ebbacf (cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2017-03-01 00:11:05 +01:00
parent cd59b4bed9
commit d74b199291
1 changed files with 2 additions and 2 deletions
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4
drivers/cpufreq/intel_pstate.c
View File

@ -2212,9 +2212,9 @@ static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
unsigned int max_freq, min_freq;
max_freq = policy->cpuinfo.max_freq *
limits->max_sysfs_pct / 100;
perf_limits->max_sysfs_pct / 100;
min_freq = policy->cpuinfo.max_freq *
limits->min_sysfs_pct / 100;
perf_limits->min_sysfs_pct / 100;
cpufreq_verify_within_limits(policy, min_freq, max_freq);
}