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| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2016-06-07 17:38:53 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-06-08 03:22:40 +0200 |
| commit | 983e600e88835f0321d1a0ea06f52d48b7b5a544 (patch) | |
| tree | 37fe9c1840d9063fb7807c7b00113718753911a4 /drivers/cpufreq/intel_pstate.c | |
| parent | 2c2c1af4497514da1be2b571066859701dd79231 (diff) | |
| download | lwn-983e600e88835f0321d1a0ea06f52d48b7b5a544.tar.gz lwn-983e600e88835f0321d1a0ea06f52d48b7b5a544.zip | |
cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo
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@linux.intel.com>
[ rjw : Subject & changelog, rewrite in fewer lines of code ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 724b9056aa6b..ee367e9b7d2e 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1561,8 +1561,11 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy) /* 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; + intel_pstate_init_acpi_perf_limits(policy); policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; cpumask_set_cpu(policy->cpu, policy->cpus); |