Re: [PATCH 4/4] arm64: dts: qcom: sa8775p-ride: Add QCS9100 compatible

[Krzysztof Kozlowski <krzk@kernel.org>]

On 12/08/2024 09:07, Tingwei Zhang wrote:
> 在 8/12/2024 2:15 PM, Krzysztof Kozlowski 写道:
>> On 12/08/2024 04:16, Tingwei Zhang wrote:
>>> On 8/8/2024 7:05 PM, Krzysztof Kozlowski wrote:
>>>> On 07/08/2024 13:04, Tingwei Zhang wrote:
>>>>> On 8/7/2024 5:35 PM, Krzysztof Kozlowski wrote:
>>>>>> On 07/08/2024 11:17, Tengfei Fan wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 8/7/2024 3:28 PM, Krzysztof Kozlowski wrote:
>>>>>>>> On 06/08/2024 06:19, Tengfei Fan wrote:
>>>>>>>>> Add QCS9100 compatible in sa8775p ride and sa8775p ride r3 board DTS.
>>>>>>>>> QCS9100 references SA8775p, they share the same SoC DTSI and board DTS.
>>>>>>>>>
>>>>>>>>
>>>>>>>> I don't understand this. You claim here that QCS9100 references SA8775p
>>>>>>>> but your diff says other way: SA8775p references QCS9100.
>>>>>>>>
>>>>>>>> Sorry, that's confusing.
>>>>>>>>
>>>>>>>> Best regards,
>>>>>>>> Krzysztof
>>>>>>>>
>>>>>>>
>>>>>>> I will update the compatible as follows to indicate that QCS9100
>>>>>>> references SA8775p.
>>>>>>>
>>>>>>> compatible = "qcom,sa8775p-ride", "qcom,qcs9100", "qcom,sa8775p";
>>>>>>
>>>>>> Is this still correct, though? sa8775p won't come with qcs9100 SoC.
>>>>> We have a new board. Hardware is same as sa877p-ride except sa8775p is
>>>>> replaced with qcs9100. We add qcs9100 SoC compatible to sa8775p-ride
>>>>
>>>> Does "new board" mean that "old board" disappears? No users to care
>>>> about it? Or just the existing board is being changed (like new revision)?
>>>
>>> We will support both boards. Sa8775p-ride board with sa8775p chipset and
>>> sa8775p-ride board with qcs9100 chipset. Both of them can be used for
>>> development.
>>
>> Patch does something else then - changes compatibles for the existing
>> (old) board.
> 
> Can you educate us the right way to add the qcs9100 SoC support in 
> sa8775p-ride board? We don't want to duplicate whole device tree file 
> since all the hardwares are same except the SoC, so we add qcs9100 SoC 
> compatible to sa8775p-ride board and still keep sa8775p SoC compatible.

Split board DTS into shared DTSI (just don't forget about proper
-M/-C/-B arguments for format-patch) and include it in relevant boards.
You also need new SoC DTSI. This will be unusual code, but it matches
what you want to achieve.

Best regards,
Krzysztof