Re: [PATCH v3 1/2] dt-bindings: soc: qcom: Add qcom,kaanapali-imem compatible

From: Krzysztof Kozlowski
Date: Tue Nov 04 2025 - 10:09:58 EST


On 04/11/2025 15:58, Konrad Dybcio wrote:
> On 11/4/25 3:52 PM, Krzysztof Kozlowski wrote:
>> On 04/11/2025 15:38, Konrad Dybcio wrote:
>>> On 11/4/25 3:37 PM, Krzysztof Kozlowski wrote:
>>>> On 04/11/2025 15:35, Konrad Dybcio wrote:
>>>>> On 11/4/25 3:26 PM, Krzysztof Kozlowski wrote:
>>>>>> This I got, but nothing here explains why you need generic compatible.
>>>>>> To re-iterate: there was no generic compatible before, now there is.
>>>>>> Writing bindings and numerous reviews from DT maintainers ask not to use
>>>>>> generic compatibles.
>>>>>
>>>>> OK so let's not worry about a generic compatible. IMEM exists since
>>>>> MSM8974 and it only had major hw updates with SM8550. They don't
>>>>> impact the software interface though, so qcom,msm8974-imem is OK.
>>>>>
>>>>> There's a separate control/status register address space for each
>>>>> instance of this IP (usually far apart from the actual SRAM pool),
>>>>> which Linux doesn't have to care about.
>>>>
>>>> Just use qcom,kaanapali-imem - that's the first device here without syscons.
>>>
>>> So we don't want to move the existing ones over?
>>
>> This was never discussed and this patch did not do it. You cannot move
>> them, that's ABI.
>
> I see, I implicitly assumed this would be a sweeping change.
>
> So should the Kaanapali submitters simply send a version of this
> patch with:
>
> - oneOf:
> - const: qcom,kaanapali-imem
> - items:
> # existing big list
>
> ?
>
> I'm not a huge fan of using kaanapali as the fallback-going-forward
> since it's literally the newest platform on the shelves (or perhaps
> not even on the shelves yet..) so it's going to look funny when
> someone comes up with support for another 2013 soc.. but perhaps
> that's just how things are supposed to be


Yes. Feel free to choose other fully compatible device as the fallback,
like you mentioned in previous email, I proposed Kaanapali as the easiest.

Best regards,
Krzysztof