[PATCH 01/10] dt/bindings: Add binding for BCM2835 mailbox driver

[Stephen Warren]

On 03/12/2015 05:23 PM, Eric Anholt wrote:
...
> The power-domain rework ended up not working out -- it needs the 
> power-domain part of device/base to support throwing -EPROBE_DEFER
> if the driver hasn't probed yet,

That makese sense.

> unless we're willing to just bake in the power domain driver in
> static init ordering.

Indeed, that's quite unlikely to be acceptable.

> Device base maintainers weren't excited about my patch for
> -EPROBE_DEFER, because then a new DT would mean we start failing to
> probe the USB driver in an older kernel, which whould be a
> regression in the case that the user had U-Boot setting up USB for
> them.

The main ABI issue is that old DTs should work with new kernels. The
other way around is nice, but certainly not as strict a requirement. I
don't think that should block a change. Do you have a link to the
thread; I don't think I noticed it.