Re: [PATCH RFC v2 2/2] Documentation: arm: define DT C-states bindings

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

Hi Mark,

On Wed, Jan 22, 2014 at 11:52:14AM +0000, Mark Brown wrote:
> On Tue, Jan 21, 2014 at 03:23:59PM +0000, Lorenzo Pieralisi wrote:
> > On Tue, Jan 21, 2014 at 02:35:11PM +0000, Amit Kucheria wrote:
> 
> > > DT-newbie here. What would happen if a vendor does not characterise
> > > the latency at each OPP? IOW, the table only contains latency values
> > > for a subset of the OPPs.
> 
> > The bindings are explicit, so the kernel will barf. Adding a LUT to map
> > latencies to OPPs make me cringe, so I would not change the current
> > bindings.
> 
> Actually looking at the OPP binding I do wonder if it might not be
> better to have a v2/rich binding for them which is extensible - the fact
> that it's not possible to add additional information seems like an
> issue, this can't be the only thing anyone might want to add and lining
> up multiple tables is never fun.

On one hand OPP bindings need improvement and that's on the cards. I am not
really following what you mean by "extensible", I only want to make sure
that the C-state bindings do not become too complex.

Do you mean extending OPP bindings to add eg C-state information there
(or whatever piece of information that is OPP dependent) ?
It seems a bit of a stretch but I can think about that.

I think that C-state properties are better defined in the C-state bindings
that was the idea but I am open to suggestions.

Thank you !
Lorenzo