Re: devicetree repository separation/migration

On Fri, Feb 21, 2014 at 11:27:29AM -0700, Warner Losh wrote:

On Feb 20, 2014, at 4:38 AM, Grant Likely wrote:

quoted

On Wed, 19 Feb 2014 13:20:15 -0800, Olof Johansson [off-list ref] wrote:

quoted

On Wed, Feb 19, 2014 at 1:12 PM, Rob Herring [off-list ref] wrote:

quoted

One way to minimize the inconvenience is keep versioning and dev
cycles in sync with the kernel. We could also start doing things to
align the kernel workflow with how things will work when we do have a
separate repository.

I don't think aligning development cycles is what we want most here it
might be useful for us in Linux but it'll make things difficult for
other projects since they're not aware of our release cycles. The
device tree bindings and DT contents in that repo should be "always
stable", i.e. no merge window / rc concept. As soon as something goes
in it's live, and from then out only fixes to the DTS files (or
appending the binding).

For example, I don't want to have to track two trees to test against
-- I'll want to keep one repo of the very latest DT files and always
use those to boot any and all boards.

This approach does have the subtle side effect that differs from what we
discussed in Edinburgh.  We've talked about always being able to boot a
new kernel on an old devicetree, but not a new devicetree on an old
kernel. With a separate board database repo we are going to hit both
cases. At least to a limited extent we're going to need older kernels
booting with the latest devicetree, and we'll need some rules about how
that gets applied.

I wasn't in Edinburgh...  Was this at the binary level or at the
source level? I'm thinking specifically about the move to cpp in the
back of my mind...

Only the binary compatibility matters. The source can change
without breaking compatibility between kernels and devicetrees.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
--
To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html