Dear Mark, On Mon, 18 Jul 2016 19:05:08 +0100 Mark Brown wrote:
> On Mon, Jul 18, 2016 at 02:44:22PM +0800, Jisheng Zhang wrote: > > > v1 and v2 and both valid voltages, but here we have an explicit limitation: > > we must take the "regulator shared" fact into consideration. Let's assume > > the voltage is at v2, devA is not busy now, it wants to scale down freq, > > then > > scale down voltage to v1, but if devB hasn't call for setting voltage to > > v1, we can't scale down voltage now, we need to wait for devB sending out > > the voltage scaling down request when it is not busy in future some time. > > Obviously, the last user will succeed to scale down the voltage. > > > My solution is > > to extend regulator_check_consumers() to check whether all consumers agree > > to scaling down voltage or not. > > I'm not sure I 100% follow your explanation above - it still sounds like > a normal shared regulator situation. In general I'm really unsure how You are right! After carefully checking the code, I found the existing regulator core could meet my what I want. Thanks so much, Jisheng > this sort of scheme is expected to work. It seems like in a lot of > cases there will be some other constraints in play (like needing to do > frequency updates as part of the sequence) which can't be handled purely > in the regulator API and/or that the DVFS driver ought to be able to use > notifiers to discover when actual changes have happened and handle > things in their own code. But like I say I don't 100% follow what's new > in your example so I may be missing something.
