tree c346d3f1add775bacbec9e0dc51f8f3e88ecfec7
parent 899bb6642f2a2f2cd3f77abd6c5a14550e3b37e6
author Rafael J. Wysocki <rafael.j.wysocki@intel.com> 1476301623 +0200
committer Rafael J. Wysocki <rafael.j.wysocki@intel.com> 1476362526 +0200

cpufreq: conservative: Fix next frequency selection

Commit d352cf47d93e (cpufreq: conservative: Do not use transition
notifications) overlooked the case when the "frequency step" used
by the conservative governor is small relative to the distances
between the available frequencies and broke the algorithm by
using policy->cur instead of the previously requested frequency
when computing the next one.

As a result, the governor may not be able to go outside of a narrow
range between two consecutive available frequencies.

Fix the problem by making the governor save the previously requested
frequency and select the next one relative that value (unless it is
out of range, in which case policy->cur will be used instead).

Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171
Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>