3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> commit 983e600e88835f0321d1a0ea06f52d48b7b5a544 upstream. When turbo is disabled, the ->set_policy() interface is broken. For example, when turbo is disabled and cpuinfo.max = 2900000 (full max turbo frequency), setting the limits results in frequency less than the requested one: Set 1000000 KHz results in 0700000 KHz Set 1500000 KHz results in 1100000 KHz Set 2000000 KHz results in 1500000 KHz This is because the limits->max_perf fraction is calculated using the max turbo frequency as the reference, but when the max P-State is capped in intel_pstate_get_min_max(), the reference is not the max turbo P-State. This results in reducing max P-State. One option is to always use max turbo as reference for calculating limits. But this will not be correct. By definition the intel_pstate sysfs limits, shows percentage of available performance. So when BIOS has disabled turbo, the available performance is max non turbo. So the max_perf_pct should still show 100%. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> [ rjw : Subject & changelog, rewrite in fewer lines of code ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> [bwh: Backported to 3.16: - limits is a perf_limits structure, not a pointer to it - Adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/cpufreq/intel_pstate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -877,8 +877,11 @@ static int intel_pstate_cpu_init(struct /* cpuinfo and default policy values */ policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling; - policy->cpuinfo.max_freq = - cpu->pstate.turbo_pstate * cpu->pstate.scaling; + update_turbo_state(); + policy->cpuinfo.max_freq = limits.turbo_disabled ? + cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; + policy->cpuinfo.max_freq *= cpu->pstate.scaling; + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; cpumask_set_cpu(policy->cpu, policy->cpus); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html