On Mon, Jul 29, 2013 at 09:31:23AM +0200, Maxime Ripard wrote:

I'm afraid this kind of use case will never be properly supported, DT
stable ABI or not.

Think about this: what kernel will actually be shipped in that board?
Most likely, it will be a BSP kernel from the vendor. Does the vendor
will have made that commitment to have a stable ABI for the DT? Will it
use the same bindings than mainline? Do we want to support all the crazy
bindings every vendor will come up with?

I'm afraid the answer to these three questions will most of the time be
"no.".

Yes, I know, and it is sad but true.
 
We can't stop the vendors from shipping half-baked BSPs. I really
don't mind that they do that. After all, they want to get *something*
working when they launch their chips.

That doesn't mean we shouldn't aim for *mainline* having a stable DT
ABI, but that kind of use case doesn't seem very realistic to me.

Right, we can and should do better. I got the beaglebone Ethernet
working in mainline (not by writing the driver, but by complaining
over and over again). I except that it will continue to work and not
fall victim to some random DT change.

Thanks,
Richard