Mark, On Thu, Dec 11, 2014 at 4:24 PM, Mark Brown <broonie at kernel.org> wrote: > On Thu, Dec 11, 2014 at 11:55:55AM -0800, Doug Anderson wrote: >> On Thu, Dec 11, 2014 at 9:09 AM, Mark Brown <broonie at kernel.org> wrote: > >> > Please also bear in mind the need to handle shared supplies in your >> > implementation. > >> I'm being dense, can you give more details? Do you want me to grab >> the mutex or do something smarter like track the voltage / tolerance >> requested by multiple clients and resolve them, or ...? > > I mean the latter - what happens if more than one consumer is trying to > use the regulator? This is IIRC why _set_voltage_tol() uses the cheap > and nasty implementation it does. Ah, I see. I don't think I've ever encountered a case where there were two consumers for a regulator that actually requested voltages... ...but isn't regulator_set_voltage_tol() broken there? If you have two clients, A and B and a regulator that can go 1.0V to 5.0V in .05V increments: A requests 1.8V +/- .1V. We get 1.8V B requests 1.7V +/- .05V. The above could be achievable with a voltage of 1.75V but it won't work with the current regulator_set_voltage_tol() I think. > There's also the potential > performance considerations for the DVS type applications now I think > about it. Iterating through voltages is really that slow? If so, perhaps we could add some caching to keep track of what voltage we actually got last time... I could also add an optimization to try the exact requested voltage right away... -Doug
