Re: [PATCH linux-next] dt-bindings: usb: snps,dwc3: correct i.MX8MQ support

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 20/03/2023 12:44, Peng Fan wrote:
>> Subject: Re: [PATCH linux-next] dt-bindings: usb: snps,dwc3: correct
>> i.MX8MQ support
>>
>> On 20/03/2023 12:02, Peng Fan wrote:
>>>> Subject: Re: [PATCH linux-next] dt-bindings: usb: snps,dwc3: correct
>>>> i.MX8MQ support
>>>>
>>>> On 20/03/2023 03:07, Peng Fan (OSS) wrote:
>>>>> From: Peng Fan <peng.fan@nxp.com>
>>>>>
>>>>> The previous i.MX8MQ support breaks rockchip,dwc3 support, so use
>>>>> select to restrict i.MX8MQ support and avoid break others.
>>>>>
>>>>> Fixes: 3754c41c7686 ("dt-bindings: usb: snps,dwc3: support i.MX8MQ")
>>>>> Signed-off-by: Peng Fan <peng.fan@nxp.com>
>>>>> ---
>>>>>  .../devicetree/bindings/usb/snps,dwc3.yaml    | 21 ++++++++++++-------
>>>>>  1 file changed, 14 insertions(+), 7 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
>>>>> b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
>>>>> index 16c7d06c9172..6347a6769ee3 100644
>>>>> --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
>>>>> +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
>>>>> @@ -28,15 +28,22 @@ allOf:
>>>>>      else:
>>>>>        $ref: usb-xhci.yaml#
>>>>>
>>>>> +select:
>>>>> +  properties:
>>>>> +    compatible:
>>>>> +      contains:
>>>>> +        enum:
>>>>> +          - fsl,imx8mq-dwc3
>>>>
>>>> And what about all snps,dwc3 devices there (without specific compatible)?
>>>> Previously they were selected and now they are not... so you just
>>>> disabled schema for all of them.
>>> [Peng Fan]
>>>
>>> I am not sure how to address:
>>>
>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore
>>> .kernel.org%2Fall%2FCAL_Jsq%2BnrqTX5ND3%3D%2BkFUmStx-
>> %2Bb%3DqpE_WsL_Le
>>> -YX8c285-
>> 5A%40mail.gmail.com%2F&data=05%7C01%7Cpeng.fan%40nxp.com%7C1e
>>>
>> 67df79692243f058fa08db2937befd%7C686ea1d3bc2b4c6fa92cd99c5c30163
>> 5%7C0%
>>>
>> 7C0%7C638149091586933618%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC
>> 4wLjAwMDAiL
>>>
>> CJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&s
>> data=r1
>>> fesB1c%2B3YxohCGM36xySFucVU25WVYIMlpgGkdoWk%3D&reserved=0
>>>
>>> Rob suggested use select, but I am not sure how to use it here. Use an
>>> extra yaml file with select or else.
>>>
>>>>
>>>>> +  required:
>>>>> +    - compatible
>>>>> +
>>>>>  properties:
>>>>>    compatible:
>>>>> -    oneOf:
>>>>> -      - items:
>>>>> -          - const: fsl,imx8mq-dwc3
>>>>
>>>> I don't understand why you remove your compatible.
>>> [Peng Fan]
>>>
>>> My last change drops 'contains' by mistake, and breaks
>>
>> This I understand.
>>
>>> rockchip,dwc3, so just bring back the original content
>>
>> This is not a reason to make your compatible undocumented. You basically
>> revert your patch. It does not make any sense to me.
> [Peng Fan] 
> 
> ok, let me think more. Honestly not have good idea (:
> If you have any guidance, that would be helpful.

You should only need a select, however most likely selecting also
snps,dwc3 (without specific compatible). Anyway this binding - including
how it is referenced by others - is getting unmanagable. I think I
commented about this on some other occasion. The point is that no one
refactors it thus it grows and grows leading to more of such tricky
scenarios.

How it should be refactored? Probably just like all other with re-usable
components: common part and device specific bindings including it. While
snps,dwc3 alone should not be allowed anymore.

Best regards,
Krzysztof