On Fri, Jul 26, 2013 at 8:21 AM, Russell King - ARM Linux
[off-list ref] wrote:

On Fri, Jul 26, 2013 at 10:14:32AM -0400, jonsmirl at gmail.com wrote:

quoted

Yes, yes - that's why the schema should be written down and used as a
validation input to dtc. Then dtc can spit out errors for non-standard
items. There would be two versions - the standard one and a legacy one
that includes the standard one plus the hacks that can't be undone.

But more importantly it provides a framework for people creating new
node definitions. Now they can't work in a vacuum and come up with
random names and structure for everything.

Most of the problems express in the thread would go away if the schema
was written down and discussed. The rule going forward would be no new
nodes that aren't part of the standard schema.

So this is why I'm seeing patches just a short time ago removing existing
compatible strings from the DT descriptions and associated driver, and
replacing them with new ones... meaning that the old DT files won't work
with newer kernels.

What that means is using the descriptions as the schema won't catch that
because they're changing those as well to match.

There's a solution to that: dtc becomes a separate project external to
the kernel which also contains the schemas that it verifies against.
That way, if you want to make changes such as that above, you need to
get it past not only kernel people but also past dtc maintainers -
which increases the chances of such stuff being caught.

+1

dtc has always been a separate project that happens to be mirrored in
the kernel tree, but the bindings need to come out be turned into
schema that can be validated.

g.