Re: [RFC PATCH 07/16] dt-bindings: pinctrl: ralink: add new compatible strings

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>]

On 02/03/2023 12:50, Arınç ÜNAL wrote:
> On 2.03.2023 14:36, Krzysztof Kozlowski wrote:
>> On 02/03/2023 11:47, Arınç ÜNAL wrote:
>>> On 2.03.2023 13:29, Krzysztof Kozlowski wrote:
>>>> On 02/03/2023 11:22, Arınç ÜNAL wrote:
>>>>>>>
>>>>>>> ## Incorrect naming
>>>>>>>
>>>>>>> MT7620, MT7621, MT7628, and MT7688 SoCs are incorrectly called Ralink,
>>>>>>> introduce new ralink->mediatek compatible strings to address it.
>>>>>>
>>>>>> So this part was addressed by Rob - we don't do it, because it does not
>>>>>> matter. Ralink is now Mediatek, thus there is no conflict and no issues
>>>>>> with different vendor used.
>>>>>
>>>>> I think Rob was rather addressing that updating compatible strings based
>>>>> on acquisition or marketing whims is not permitted. This condition does
>>>>> not apply here as these SoCs were never Ralink.
>>>>>
>>>>> I understand your point that Ralink is now MediaTek but still, calling
>>>>> these SoCs Ralink would be a bit misleading, don't you think?
>>>>
>>>> Misleading yes, but also does not matter. At least matter not enough to
>>>> justify ABI break, so you would need to deprecate old ones and keep
>>>> everything backwards compatible. You still would affect 3rd party users
>>>> of DTS, though...
>>>
>>> I intend to do just that. Introduce new mediatek strings, keep the old
>>> ones so it's backwards compatible, therefore don't break the ABI.
>>>
>>> Instead of deprecating old strings, I intend to introduce the checks I
>>> mentioned, on the schema, so the pin muxing bindings only apply if the
>>> DT has got a string that won't match multiple schemas. This way it
>>> shouldn't affect 3rd party DTs.
>>
>> I meant, 3rd party users of DTS. You will replace the compatible in the
>> DTS, right? So the DTS exported and used in all other projects, OS,
>> firmwares, bootloaders, out of tree kernel forks will stop working.
> 
> I plan to change it on the DTs for MediaTek SoCs, yes. Is this a 
> problem? From what I can tell, what must be ensured is that old DTs must 
> work with newer kernels, not new DTs on older kernels.

Can I be clearer than this?

" So the DTS exported and used in all other projects, OS,
firmwares, bootloaders, out of tree kernel forks will stop working."

Yes, this is a problem - they will stop working.

Best regards,
Krzysztof