[U-Boot] [PATCH 2/8] ARM: PSCI: Alow arch specific DT patching

Mark Rutland
2014-08-28T12:47:41Z

On Thu, Aug 28, 2014 at 11:51:08AM +0100, Arnab Basu wrote:
> Hi Mark
>
> On 08/28/2014 03:40 PM, Mark Rutland wrote:
> > Hi Arnab,
> >
> > On Wed, Aug 27, 2014 at 09:29:55PM +0100, Arnab Basu wrote:
> >> Both ARMv7 and ARMv8 need to patch the device tree but the kind
> >> of patching done is different. This creates a function that can be
> >> defined by each architecture to handle the differences
> >
> > I have no problem with the patch, but what is it that we need to do
> > differently for ARMv7 and ARMv8?
> >
>
> In ARMv7 there does not seem to be any code around to set
> "enable-method" to "spin-table". I guess it is assumed that DTs already
> come with this set.

That'll be a consequence of partial conversion frmo board file on the
32-bit side. For most platforms the SMP boot mechanism is still
implicit.

> For ARMv8 we would like to assume that "enable-method" is missing from
> the cpu node and will be set either to "spin-table" or "psci" by the
> boot loader.

Sounds good to me.

> So the difference is, for ARMv7 the "enable-method" is only modified in
> case of PSCI, whereas for ARMv8 it is always modified.

Ok. Thanks for the description. :)

Mark.