Re: [PATCH v3 2/9] dt-bindings: display: add verisilicon,dc

Krzysztof Kozlowski
2025-11-27T13:59:02Z

On 27/11/2025 14:47, Icenowy Zheng wrote:
> 在 2025-11-26星期三的 11:22 +0100，Krzysztof Kozlowski写道：
>> On 26/11/2025 10:50, Icenowy Zheng wrote:
>>>>> +maintainers:
>>>>> +  - Icenowy Zheng <uwu@icenowy.me>
>>>>> +
>>>>> +properties:
>>>>> +  $nodename:
>>>>> +    pattern: "^display@[0-9a-f]+$"
>>>>> +
>>>>> +  compatible:
>>>>> +    items:
>>>>> +      - enum:
>>>>> +          - thead,th1520-dc8200
>>>>> +      - const: verisilicon,dc
>>>>
>>>> I do not see any explanation of exception for generic
>>>> compatibles,
>>>> maybe
>>>> except "self-identification" remark. Rob already pointed this
>>>> out, so
>>>> be
>>>> explicit in commit msg why you are using a generic compatible.
>>>
>>> Well I only get the meaning of "a SoC specific compatible is
>>> required"
>>> in his review message.
>>>
>>> I think my binding now requires both a SoC-specific compatible and
>>> a
>>> generic compatible, which should be okay to satisfy Rob's original
>>> review.
>>
>> You will get then the same questions for me - what justifies generic
>> compatible. You should be on this explicit, because otherwise people
>> misinterpret some commits and patches, and they think the generic
>> compatible is allowed for them as well.
>
> I came across a comment on Mali Valhall bindings that says `Mali
> Valhall GPU model/revision is fully discoverable`, just after the
> compatible string.
>
> Should I add a comment like this, or should I make things more clear in
> the commit message?

Just say in the commit msg in the sentence about "self-identification
facility" that therefore you use generic compatible (or "generic
compatible is suitable").

Please trim the context when replying. Look below:

>
>>
>>>
>>>>
>>>>> +
>>>>> +  reg:
>>>>> +    maxItems: 1
>>>>> +
>>>>> +  interrupts:
>>>>> +    maxItems: 1
>>>>> +
>>>>> +  clocks:
>>>>> +    minItems: 4
>>>>
>>>> This is not flexible. Device either has or has not these clocks.
>>>
>>> The existence of all these clocks are verified by diagrams in
>>> manuals
>>
>> So not flexible, then:
>>
>>> of two different SoCs with DC8200 (T-Head TH1520 and StarFive
>>> JH7110).
>>>
>>> Maybe a explicit `maxItems: 5` is needed here, but as my DT passes
>>> dtbs_check, I don't think it's necessary?
>>
>> No, drop minItems only.
>>
>>>
>>> Or maybe I should drop the flexibility now and use a `minItems: 5`
>>> here
>>> (and leave DC8000 support as another story)? (The Eswin EIC7700
>>> manual
>>> does not have a diagram showing external connections of the DC,
>>> like
>>> the two SoCs I mentioned above).
>>
>> You document here only the devices explicitly mentioned in the
>> binding.
>> You cannot add here constraints or clocks for some device which is
>> not
>> in the binding and I see only th1520 in the binding.
>>
>> Best regards,
>> Krzysztof
>

Is all this needed for me? If it is there I will waste time scrolling
through it looking for your questions.

Think how your patchset and replies are received by reviewer.

Best regards,
Krzysztof