[PATCH v4 14/34] drm/exynos: hdmi: remove the i2c drivers and use devtree

[Tomasz Figa]

On 12.02.2014 00:02, Olof Johansson wrote:
> On Fri, Feb 7, 2014 at 6:52 PM, Tomasz Figa <tomasz.figa at gmail.com> wrote:
>
>> Adding new required properties to an already defined binding is breaking
>> backwards compatibility, which is supposed to be preserved, since DT is an
>> ABI.
>>
>> Now, I'm not really a big fan of DT stability, but if we decide to maintain
>> it for other Exynos drivers as well (e.g. USB), then we probably should do
>> the same here...
>
> A binding without users _can_ be changed.

Of course it can. However hdmi binding apparently already has users, 
since git grep hdmi over Exynos dts files shows 4 boards using HDMI, so 
I'm not sure it's the case here.

> If you're sure that there
> are no users of the old binding, and that any users can and will
> (without complaint or surprise) update to a newer DT with the newer
> binding, then you can change it. I'm not sure if the cat is out of the
> bag w.r.t. users of upstream Exynos kernels that this is true or not.

The question is whether there are really users of upstream kernels that 
would care, i.e. don't always simply use DTB and kernel built from the 
same tree.

Best regards,
Tomasz