On 10-08-21, 10:17, Lukasz Luba wrote: > Hi Viresh, > > I like the idea, only small comments here in the cover letter. > > On 8/10/21 8:36 AM, Viresh Kumar wrote: > > Provide a cpufreq driver flag so drivers can ask the cpufreq core to register > > with the EM core on their behalf. This allows us to get rid of duplicated code > > in the drivers and fix the unregistration part as well, which none of the > > drivers have done until now. > > The EM is never freed for CPUs by design. The unregister function was > introduced for devfreq devices. I see. So if a cpufreq driver unregisters and registers again, it will be required to use the entries created by the registration itself, right ? Technically speaking, it is better to unregister and free any related resources and parse everything again. Lets say, just for fun, I want to test two copies of a cpufreq driver (providing different set of freq-tables). I build both of them as modules, insert the first version, remove it, insert the second one. Ideally, this should just work as expected. But I don't think it will in this case as you never parse the EM stuff again. Again, since the routine is there already, I think it is better/fine to just use it. > > This would also make the registration with EM core to happen only after policy > > is fully initialized, and the EM core can do other stuff from in there, like > > marking frequencies as inefficient (WIP). Though this patchset is useful without > > that work being done and should be merged nevertheless. > > > > This doesn't update scmi cpufreq driver for now as it is a special case and need > > to be handled differently. Though we can make it work with this if required. > > The scmi cpufreq driver uses direct EM API, which provides flexibility > and should stay as is. Right, so I left it as is for now. -- viresh
