[PATCH 2/4] cpufreq: intel_pstate: Lower frequency than expected under no_turbo

From: Srinivas Pandruvada
Date: Wed Jan 18 2017 - 13:50:51 EST


When turbo is not disabled by BIOS, but user disabled from intel P-State
sysfs and changes max/min using cpufreq sysfs, the resultant frequency
is lower than what user requested.

The reason for this, when the perf limits are calculated in set_policy()
callback, they are with reference to max cpu frequency (turbo frequency
), but when enforced in the intel_pstate_get_min_max() they are with
reference to max available performance as documented in the intel_pstate
documentation (in this case max non turbo P-State).

This needs similar change as done in intel_cpufreq_verify_policy() for
passive mode. Set policy->cpuinfo.max_freq based on the turbo status.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index a54d65a..a5f1a04 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2042,6 +2042,20 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)

static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
{
+ struct cpudata *cpu = all_cpu_data[policy->cpu];
+ struct perf_limits *perf_limits;
+
+ if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
+ perf_limits = &performance_limits;
+ else
+ perf_limits = &powersave_limits;
+
+ update_turbo_state();
+ policy->cpuinfo.max_freq = perf_limits->turbo_disabled ||
+ perf_limits->no_turbo ?
+ cpu->pstate.max_freq :
+ cpu->pstate.turbo_freq;
+
cpufreq_verify_within_cpu_limits(policy);

if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
--
2.7.4