intel_pstate: honor user space min_perf_pct override on resume

If the user has requested an override of the min_perf_pct via
sysfs, then it should be restored whenever policy is updated,
such as on resume.  Take the max of whatever the user requested
and whatever the policy is.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index dfee5725903b..e7e808d9a8af 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -148,6 +148,8 @@ struct perf_limits {
         int32_t min_perf;
         int max_policy_pct;
         int max_sysfs_pct;
+        int min_policy_pct;
+        int min_sysfs_pct;
 };
 
 static struct perf_limits limits = {
@@ -159,6 +161,8 @@ static struct perf_limits limits = {
         .min_perf = 0,
         .max_policy_pct = 100,
         .max_sysfs_pct = 100,
+        .min_policy_pct = 0,
+        .min_sysfs_pct = 0,
 };
 
 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
@@ -431,7 +435,9 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
         ret = sscanf(buf, "%u", &input);
         if (ret != 1)
                 return -EINVAL;
-        limits.min_perf_pct = clamp_t(int, input, 0 , 100);
+
+        limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
+        limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 
         if (hwp_active)
@@ -921,6 +927,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 
         if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
             policy->max >= policy->cpuinfo.max_freq) {
+                limits.min_policy_pct = 100;
                 limits.min_perf_pct = 100;
                 limits.min_perf = int_tofp(1);
                 limits.max_policy_pct = 100;
@@ -930,8 +937,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
                 return 0;
         }
 
-        limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
-        limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
+        limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
+        limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
+        limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 
         limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;