Message-ID: <ea5d7622-ef9d-4bfc-af64-87bd19664333@linaro.org>
Date: Thu, 26 Jun 2025 14:17:23 +0300
From: Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>
To: Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
 Krzysztof Kozlowski <krzk@...nel.org>, vincent.knecht@...loo.org,
 Robert Foss <rfoss@...nel.org>, Todor Tomov <todor.too@...il.com>,
 Mauro Carvalho Chehab <mchehab@...nel.org>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Bjorn Andersson <andersson@...nel.org>,
 Konrad Dybcio <konradybcio@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
 linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
 André Apitzsch <git@...tzsch.eu>,
 phone-devel@...r.kernel.org, ~postmarketos/upstreaming@...ts.sr.ht,
 Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Subject: Re: [PATCH v5 3/4] media: dt-bindings: Add qcom,msm8939-camss

On 6/26/25 13:48, Bryan O'Donoghue wrote:
> On 26/06/2025 11:28, Krzysztof Kozlowski wrote:
>> On 26/06/2025 12:19, Bryan O'Donoghue wrote:
>>> On 26/06/2025 11:00, Krzysztof Kozlowski wrote:
>>>>> +  reg-names:
>>>>> +    items:
>>>>> +      - const: csi_clk_mux
>>>> No, I already provided arguments in two lengthy discussions - this is
>>>> not sorted by name.
>>>>
>>>> Keep the same order as in previous device, so msm8916 for example. Or
>>>> any other, but listen to some requests to sort it by some arbitrary rule
>>>> which was never communicated by DT maintainers.
>>>
>>> I don't think if you look through the history that you can find a
>>> consistent rule that was used to arrange the registers.
>>>
>>> So we are trying to have a consistent way of doing that. Thats why the
>>> last number of additions have been sort by name, because it seemed to be
>>> the most consistent.
>>
>>
>> Why are we discussing it again? You asked me the same here:
>> https://lore.kernel.org/all/8f11c99b-f3ca-4501-aec4-0795643fc3a9@kernel.org/
>>
>> and I already said - not sorting by name. You take the same order as
>> previous.
>>
>> If you ever want to sort by name, answer to yourself:
>> NO. Take the same order as other existing device.
>>
>> If you ever want to sort by value, answer to yourself:
>> NO.
>>
>> You both came with some new, invented rules of sorting, applied it, and
>> now you claim that "existing devices were sorted like that". What? NO!
>>
>> Best regards,
>> Krzysztof
> 
> OK.
> 
> Discussed this on Slack with Krzysztof.

The problem with private communications is that it produces
sacral knowledge.

> 8939 should be like 8916 because these are devices of a similar class.
> 

What's about MSM8953 then?

Please see commit c830aff08d51 ("media: dt-bindings: Add qcom,msm8953-camss").

> x1e has a particular order if a new device x1e+1 comes along with a new
> register then
> 

> 
> I think I personally haven't understood what was meant by "devices of a
> class" but its clearer now.
> 

And I still didn't get it, how to read this "devices of a class"?

In particular why is MSM8939 a device of MSM8916 class and MSM8953 is
not?

For sake of simplicity I list only accepted CAMSS dt bindings:

qcom,msm8916-camss.yaml
qcom,msm8953-camss.yaml
qcom,msm8996-camss.yaml
qcom,sc7280-camss.yaml
qcom,sc8280xp-camss.yaml
qcom,sdm660-camss.yaml
qcom,sdm670-camss.yaml
qcom,sdm845-camss.yaml
qcom,sm8250-camss.yaml
qcom,sm8550-camss.yaml
qcom,x1e80100-camss.yaml

I kindly ask to select a number of class defining IPs from the list,
so that all next ones will derive from those only, and not from
"another class". It's a task for a DT maintainer I presume.

Before completing this and getting a common understanding all next
work to provide CAMSS suppor for new platforms is not directed by
any policy, because the policy "do as it's been done before" is
applied inconsistently.

-- 
Best wishes,
Vladimir

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