cpufreq: interactive:call __cpufreq_driver_target() for cur frequency
There is a race window as explained below when governor tries to change the cpu frequency and some other thread (say thermal mitigation) try to change the policy limits simultaneously. speedchange task (ThreadA) Thread B(say Thermal) cpufreq_interactive_speedchange_task() | __cpufreq_driver_target() | set_cpu_freq() | cpufreq_update_policy() | modified policy_max | check policy->curr against new policy limits,return without calling __cpufreq_driver_target as policy->curr(which is not updated by ThreadA) is still within the new policy limits. | sent CPUFREQ_POSTCHANGE notification | updated policy->cur which happens to be higher than policy->max This results the current frequency being higher than the policy->max and violating the policy limits. This causes thermal impact and in turn high power consumption. So Fix this by calling __cpufreq_driver_target() always with current frequency and leave it to __cpufreq_driver_target() to guarantee there is no race condition when multiple threads are changing frequencies. Change-Id: I9136e9245677e8fc90a628d3099aca8d63d3677c Signed-off-by:Hanumath Prasad <hpprasad@codeaurora.org> Used commit: https://github.com/flar2/kernel-msm/commit/352989e25aba22221d098ef612759dfb637dcf4e
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