On 15/10/2020 11:00, Lukasz Luba wrote: [ ... ] >> There is the SCMI and the DT. Because there are two sources where it is >> impossible to know if they are using the same units, we are stuck to >> ensure a consistency for the kernel. >> >> The platform should use: >> - the SCMI only (scaled or real) >> - the DT only (real) >> [ - the firmware file only (scaled or real) ] >> > > Do you mean by SCMI - registration using em_dev_register_perf_domain() ? It was high level description, but yes, I guess it is the case. >> As it is not possible to know if they are scaled or real, there is no >> choice except making them mutually exclusive. > > So you propose a bit more restriction in registration EM, to not get > lost in the future. I also have these doubts. Let's consider it and > maybe agree. > > I've recommended Qcom to use em_dev_register_perf_domain() when they > have this obfuscated power values. Then any developer in the future > who wants to add EM for a new device on that platform, should use the > em_dev_register_perf_domain(). > > In this case the flag in EM that you have proposed makes sense. > We probably need an argument 'bool abstract_scale' in the > em_dev_register_perf_domain(..., bool abstract_scale) > as a source of information. I was suggesting to add a flag to the em_perf_domain structure giving the source of the power numbers. So if the IPA is having the 'sustainable-power' set in DT but the em_perf_domain is flagged with power number coming from SCMI, then they will be incompatible, the thermal zone will fail to register. > We would allow to co-exist em_dev_register_perf_domain(..., false) > with dev_pm_opp_of_register_em() EM devices. > > Is it make sense? Well, it does not change my opinion. We should assume the energy model is always milliwatts. If the SoC vendors find a way to get around with bogoWatts, then good to them and up to them to deal with in the future. -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
