Changes

As stated before, automatic configuration by measuring system load, cannot be done performed for some elements or is not useful in many situations (e.geg. realtime video stream processing).

What is useful A suggested approach is to choose a set-point for each subsystem that has enough processing power to do the required work (e.geg. without loosing video frames) but while minimizing the power consumption.

The situation is even harder to manage to because of internal system constraint: changing the frequency for a subsystem requires changing its power supply (as a rule of thumb, higher power supply is required to have a stable higher frequency). There are some other restriction restrictions that does do not allow the user to select arbitrary settings on different subsystems (which will would lead to system instability).

For it's [[:Category:Naon|Naon]] platform, Dave provides a ''custom'' PM driver that allow to chooseallows for selection, at runtime, of an OPP for each subsystem (Cortex A8, CORE, DSP, HDVICP) that already configure providing a default stable voltage/frequency setting. Some OPPs are directly derived from the one ones officially supported by TI (see DM814x TRM at DVFS section, for example) plus and some other custom OPP OPPs provided by Dave.