Re: [PATCH v2 08/12] ARM: dts: imx6dl-pico: fix board compatibles

From: Ahmad Fatoum
Date: Fri Oct 02 2020 - 03:41:37 EST


Hello,

On 10/1/20 12:37 PM, Krzysztof Kozlowski wrote:
>> The existing binding doesn't cover these boards then and needs to be
>> extended, no? How about following patch?
>
> What do you mean it doesn't cover? It was added exactly to handle them:
> + - technexion,imx6q-pico-dwarf # TechNexion i.MX6Q Pico-Dwarf
> + - technexion,imx6q-pico-hobbit # TechNexion i.MX6Q Pico-Hobbit
> + - technexion,imx6q-pico-nymph # TechNexion i.MX6Q Pico-Nymph
> + - technexion,imx6q-pico-pi # TechNexion i.MX6Q Pico-Pi
>

Still they are unused. So I'd think these boards should be handled like boards
that predated bindings: a binding is written that doesn't break existing users.

>> [I guess we need to keep the two-compatible list they were originally
>> in for compatibility even if it's unused among upstream device trees?]
>
> You want to change both the binding (thus breaking the ABI) and update
> the DTS to reflect new ABI. Then why having a binding at all?

If we leave the old two-compatible enumeration intact, there is no ABI broken.

> I would assume that either binding is correct or DTS. You propose that
> both are wrong and both need changes... in such case this is clearly
> broken.

IMO the DTS is the correct one. If you want to honor the author's intention
that each base board has a different compatible, it should be an extra
compatible and not replace the existing one that may be already in use.

Cheers
Ahmad


>
> Best regards,
> Krzysztof
>

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