On Wed, 12 Dec 2018 at 19:32, Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > Quoting Rajendra Nayak (2018-12-11 20:13:13) > > > > >>> Just to make sure there are no conflicting hierarchical constraints > > >>> between idle management and performance state management!? > > >>> > > > > > > I'm not sure what idle states mean to the CX and MX domains. Would it be > > > some sort of idle state governor attached at genpd creation time that > > > would adjust the main SoC power rails when all devices attached are > > > idle? Maybe I don't understand how idle states are different from > > > performance states. > > > My understanding is that devices using these domains would almost always > > > expect their clk frequency and clk on/off state to decide what the > > > performance state is, unless they need to ignore clk state because they > > > aren't managing clks and bump up the voltage directly when the device is > > > active. Either way, devices are actively managing the voltage they need > > > these voltage domains to operate at by using the genpd performance > > > states APIs. > > > > I am not quite sure whats the point that you are trying to make here, > > but this is what I would expect the users of these genpds to do, > > regardless of if they have a clk dependency or not. > > When the device is active, vote for a performance state they need > > then request for the genpd to be on. When they are idle, request for the > > genpd to be turned off. > > > > I believe Ulf is asking because he's proposing to make genpd idle states > and genpd performance states orthogonal to each other. And to also make > performance states unaffected by the on/off state of the genpd. Yes, that's one of the reasons. Anyway, I appreciate both of yours descriptive feedback, no further worries from my side! Kind regards Uffe
