On Tue, Dec 10, 2019 at 12:41:47PM +0000, Vaittinen, Matti wrote:

> The thing is that if we do initial setting of voltages (based on
> binding data) we can set the voltages to registers before we switch to
> that run-level. If we don't do initial setting then we will only do
> setting when voltage change is actually requested - which may be too
> late. (I actually heard somewhere that there is 40 uS time limit - but
> I don't see how this is counted. Starting from what? - and I don't see
> how this is guaranteed even with GPIO if interrupts are to be served).

I suspect that if that limit is a real thing it's from some runtime
performance metrics where people are doing benchmarking to verify that
everything is working fine rather than an absolute thing that is a basic
requirement for operation.

> So, I am again wondering if I should just upstream the basic control
> with I2C for SoCs which do not require fast DVS voltage changes and
> perhaps maintain/provide own set of patches with additional interface
> for run-level control for those customers who require it... Sorry for
> being such a difficult guy. Decision making seems to not be my strong
> point :/

Yes, definitely submit the basic stuff separately - the GPIO changes can
be reviewed as a separate, incremental patch.