cpufreq: intel_pstate: Fix intel_pstate_verify_policy()

The code added to intel_pstate_verify_policy() by commit 1443ebbacfd7
(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: 1443ebbacfd7 (cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy)
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 436a4c5..3dc5466 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -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);
        }