Re: [PATCH v2 8/9] media: dt-bindings: Add Intel Displayport RX IP

Krzysztof Kozlowski
2024-02-26T12:06:34Z

On 26/02/2024 11:59, Paweł Anikiel wrote:
>>> +properties:
>>> + compatible:
>>> + const: intel,dprx-20.0.1
>>> +
>>> + reg:
>>> + maxItems: 1
>>> +
>>> + interrupts:
>>> + maxItems: 1
>>> +
>>> + intel,max-link-rate:
>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>> + description: Max link rate configuration parameter
>>
>> Please do not duplicate property name in description. It's useless.
>> Instead explain what is this responsible for.
>>
>> Why max-link-rate would differ for the same dprx-20.0.1? And why
>> standard properties cannot be used?
>>
>> Same for all questions below.
>
> These four properties are the IP configuration parameters mentioned in
> the device description. When generating the IP core you can set these
> parameters, which could make them differ for the same dprx-20.0.1.
> They are documented in the user guide, for which I also put a link in
> the description. Is that enough? Or should I also document these
> parameters here?

user-guide is something for users, like user-space programmers or
end-users. I would never open it to look for any information related to
hardware.

Anyway, external resources are a no-go. We have it clearly in submitting
patches:

https://elixir.bootlin.com/linux/v6.8-rc6/source/Documentation/process/submitting-patches.rst#L130

>
>>
>>> +
>>> + intel,max-lane-count:
>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>> + description: Max lane count configuration parameter
>>> +
>>> + intel,multi-stream-support:
>>> + type: boolean
>>> + description: Multi-Stream Transport support configuration parameter
>>> +
>>> + intel,max-stream-count:
>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>> + description: Max stream count configuration parameter
>>> +
>>> + port:
>>> + $ref: /schemas/graph.yaml#/properties/port
>>> + description: SST main link
>>
>> I don't understand why you have both port and ports. Shouldn't this be
>> under ports?
>
> I put both so that you can use the shorter port property when the
> device only has one port (i.e. no MST support). It would work fine
> without it. If you think that's unnecessary, I can remove it (and use
> the ports property even if there is only one).

No, it is fine, but then you need allOf: which will restrict to only one
of them: either port or ports.

Best regards,
Krzysztof