[PATCH V3 0/6] ARM64: Add support for FSL's LS2085A SoC

Catalin Marinas
2014-09-09T13:42:26Z

On Tue, Sep 09, 2014 at 12:46:18PM +0100, bhupesh.sharma at freescale.com wrote:
> > On Thursday 04 September 2014 10:13:19 Mark Rutland wrote:
> > > On Wed, Sep 03, 2014 at 07:31:44PM +0100, Arnd Bergmann wrote:
> > > > On Wednesday 03 September 2014 17:31:30 Mark Rutland wrote:
> > > > >
> > > > > However, I'm not sure I follow the reasoning for making this
> > > > > significantly harder, and even ignoring that I don't think this
> > > > > does make things significantly harder. Especially so if we have a
> > > > > PSCI node but not an enable method -- in that case its trivial to
> > > > > patch in an unrelated enable-method anyhow.
> > > >
> > > > Right, it's not actually much harder. A better way to look at it is
> > > > probably that we document what which parts we expect to stay
> > > > constant and which parts are to be filled out by the boot loader.
> > > > Independent of what PSCI implementation the boot loader provides, we
> > > > would like to see enable-method="psci".
> > >
> > > So in the /cpus node, have a comment like:
> > >
> > > /*
> > > * We expect the enable-method to be "psci", but this is dependent on
> > > * the FW, which will fill this in.
> > > */
> >
> > I was thinking of leaving the enable-method in the cpus node, but having
> > an empty psci node with a similar comment.
> >
> > > Or, should we put together a soc-guidance.txt with that, ensuring
> > > things are initialised correctly (CNTVOFF, CNTFREQ), etc?
> >
> > I would very much welcome documentation like that!
>
> Is this documentation planned (already being worked upon), or should I
> try to spin-out a RFC patch which tries to add this guidance
> documentation.

RFCs are welcome. We had such thing on the random to-do list of the day
but never got to write anything down. As Stuart mentioned, it would be
better to add it as part of the booting.txt document. A potential
soc.txt is more for DT, code structuring (spreading) throughout drivers/
etc. If you have time, that would be good as well ;).

--
Catalin