diff options
author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2016-06-07 17:38:53 -0700 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-06-08 03:22:40 +0200 |
commit | 983e600e88835f0321d1a0ea06f52d48b7b5a544 (patch) | |
tree | 37fe9c1840d9063fb7807c7b00113718753911a4 /include/linux | |
parent | 2c2c1af4497514da1be2b571066859701dd79231 (diff) |
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 'include/linux')
0 files changed, 0 insertions, 0 deletions