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Subject: Re: [PATCH 07/18] MIPS: DTS: jz4780: fix otg node as reported by
 dtbscheck
To:     "H. Nikolaus Schaller" <hns@goldelico.com>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Paul Cercueil <paul@crapouillou.net>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-mips@vger.kernel.org, letux-kernel@openphoenux.org
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From:   Zhou Yanjie <zhouyanjie@wanyeetech.com>
Message-ID: <3e088e18-5df9-bf50-0070-b24b8a3c5f41@wanyeetech.com>
Date:   Tue, 12 Apr 2022 17:49:07 +0800
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Hi Nikolaus,

On 2022/4/11 上午3:13, H. Nikolaus Schaller wrote:
> Hi,
>
>> Am 10.04.2022 um 18:32 schrieb Zhou Yanjie <zhouyanjie@wanyeetech.com>:
>>
>> Hi folks,
>>
>> On 2022/4/9 下午9:53, H. Nikolaus Schaller wrote:
>>>> Am 09.04.2022 um 15:44 schrieb Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>:
>>>>
>>>> On 09/04/2022 15:32, H. Nikolaus Schaller wrote:
>>>>>> Am 09.04.2022 um 15:15 schrieb Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>:
>>>>>>
>>>>>> On 09/04/2022 15:05, H. Nikolaus Schaller wrote:
>>>>>>>> This looks wrong, the block usually should have a specific compatible.
>>>>>>>> Please mention why it does not.
>>>>>>> Well, I did not even have that idea that it could need an explanation.
>>>>>>>
>>>>>>> There is no "ingenic,jz4780-otg" and none is needed here to make it work.
>>>>>> Make it work in what terms? We talk about hardware description, right?
>>>>> Yes.
>>>>>
>>>>>>> Therefore the generic "snps,dwc2" is sufficient.
>>>>>> No, you are mixing now driver behavior (is sufficient) with hardware
>>>>>> description.
>>>>> No. "snps,dwc2" is a hardware description for a licensed block.
>>>>> Not a driver behavior.
>>>> snps,dwc2 matches the original block, not necessarily this
>>>> implementation. Unless you are sure?
>>> I assume. Nobody has reported an issue without having any specific jz4780 driver in place.
>>> Well, that is only evidence, not bullet proof.
>>>
>>>>>> Most of licensed blocks require the specific compatible to
>>>>>> differentiate it.
>>>>> If there is a need to differentiate.
>>>> No, regardless whether there is a need currently, most of them have
>>>> specific compatibles, because there are some minor differences. Even if
>>>> difference is not visible from programming model or wiring, it might
>>>> justify it's own specific compatible. For example because maybe once
>>>> that tiny difference will require some changes.
>>>>
>>>> Someone added the ingenic compatible, so why do you assume that one tool
>>>> (bindings) is correct but other piece of code (using specific
>>>> compatible) is not? You use the argument "bindings warning" which is not
>>>> enough. Argument that blocks are 100% same, is good enough, if you are
>>>> sure. Just use it in commit msg. But are you sure that these are the
>>>> same? Same pins, same programming model (entire model, not used by Linux)?
>>> The compatible ingenic,jz4780-otg was introduced in 158c774d3c64859e84dd20e04d5fb18c8d3d318e.
>>> Hence I have added Yanjie for clarification why he added it in the .dts and not in the bindings.
>>
>> It's my fault, last year I made an OTG driver for Ingenic SoCs and sent it
>> to the mailing list, and then I received some revision comments, but for
>> some personal reasons I didn't continue to improve it.
>>
>> I'll finish these modifications as soon as possible and send them out.
>> Then after they merge into the mainline, this problem will be solved.
> No need to apologize.
>
> If you agree I can add "ingenic,jz4780-otg" to the schema file and keep
> the .dts in the v2 of my series.


Sure.

Or you can wait a bit, I plan to send out new patches later today, it 
contains "ingenic,jz4780-otg".


> And I'll add you to the list of reviewers, so you can please comment v2
> if it is correct or if we are still missing something.


Okay, thanks!


>
> Best regards and thanks,
> Nikolaus