[PATCH 3/4] cpufreq: intel_pstate: Make HWP limits compatible with legacy

From: Srinivas Pandruvada
Date: Wed Jan 18 2017 - 13:51:28 EST


Under HWP the performance limits are calculated using max_perf_pct
and min_perf_pct using possible performance, not available performance.
The available performance can be reduced by no_turbo setting. To make
compatible with legacy mode, use max/min performance percentage with
respect to available performance.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index a5f1a04..095bcaf 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -873,7 +873,10 @@ static void intel_pstate_hwp_set(struct cpufreq_policy *policy)

rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
hw_min = HWP_LOWEST_PERF(cap);
- hw_max = HWP_HIGHEST_PERF(cap);
+ if (limits->no_turbo)
+ hw_max = HWP_GUARANTEED_PERF(cap);
+ else
+ hw_max = HWP_HIGHEST_PERF(cap);
range = hw_max - hw_min;

max_perf_pct = perf_limits->max_perf_pct;
@@ -887,11 +890,6 @@ static void intel_pstate_hwp_set(struct cpufreq_policy *policy)

adj_range = max_perf_pct * range / 100;
max = hw_min + adj_range;
- if (limits->no_turbo) {
- hw_max = HWP_GUARANTEED_PERF(cap);
- if (hw_max < max)
- max = hw_max;
- }

value &= ~HWP_MAX_PERF(~0L);
value |= HWP_MAX_PERF(max);
--
2.7.4