Re: RFC: Location for Device Tree Sources?

On Fri, Aug 04, 2006 at 02:49:00PM +1000, Paul Mackerras wrote:

Tom Rini writes:

quoted

But "content requirements change" isn't the same as "left things out of
their tree".  It sounds, and I haven't seen the changes, so I'm not
certain that the meaning behind a field changed.  Something like that
should change the dt version.

I disagree.  Strongly.  The dt version relates to the representation
of the tree, not its content.

But doesn't the representation include meaning?

If we *have* to change the meaning of a property value in a particular
node in an incompatible way, then we can do something such as adding
another property to indicate what the interpretation of the first
property value should be.  Usually it's possible to find a way around
the problem without resorting to that, though.

Agreed.  Kicking myself for not being explicit enough :)

quoted

 New fields aren't a problem.  Changing
existing fields meaning in incompatible ways is a problem.

Only a minor, localized problem.  Nothing worth changing the whole dt
version number for.

I'll rephrase what I said to what I think we all agree.  Changing
existing fields meanings in incompatible ways and not somehow allowing
that to still work (like by adding a flag so new trees are interpreted
one way, old trees are fixed-up or whatever) is a problem.

-- 
Tom Rini