Colleagues in the system framework layer want to raise the CPU to the maximum frequency in some scenarios (mainly cold start) and keep it for a period of time. However, in the current mtk platform, thermal has higher priority than boost, so it is necessary to upgrade the priority of boost nodes in the driver layer.

Taking cold start boosting as an example, the software calling process is as follows.

Add the/proc/ppm/policy/forcelimit _ CPU _ freq node to the kernel layer.

Because the default proc node has lower priority than the thermal node, a node with higher priority is added.

The main structure driven by Mtk ppm policy is ppm_policy_data.