Re: [PATCH v2 1/2] dt-bindings: mailbox: qcom: Add IPCC support for Kaanapali Platform

[Krzysztof Kozlowski <krzk@kernel.org>]

On 29/10/2025 17:15, Bjorn Andersson wrote:
> On Wed, Oct 29, 2025 at 04:47:17PM +0100, Krzysztof Kozlowski wrote:
>> On 29/10/2025 16:16, Bjorn Andersson wrote:
>>> On Wed, Oct 29, 2025 at 01:15:09AM -0700, Jingyi Wang wrote:
>>>> Add the physical client ids and binding for Kaanapali platform. Physical
>>>> client IDs instead of virtual client IDs are used for qcom new platforms
>>>> in the Inter Process Communication Controller (IPCC) driver as virtual to
>>>> physical mapping logic is removed in HW.
>>>
>>> Happy to see the description of what changed wrt physical vs virtual
>>> client IDs, but you're leaving the task of figuring out how this
>>> explanation is applicable to the imagination of the reader.
>>>
>>> Nobody knows that the values in dt-bindings/mailbox/qcom-ipcc.h are
>>> "virtual client IDs", so it's not clear that you're trying to provide an
>>> explanation to why a new, platform-specific, header file is needed here.
>>>
>>>
>>
>>
>> Physical or virtual, standard expectation is that they are used by the
>> driver. This does not happen here, so what do they exactly represent?
>> Which part of SW ABI?
>>
> 
> I was under the impression that they would be used only in DeviceTree
> source, and the driver simply uses the values it reads at runtime.


And uses them for what? What do the values mean for the driver, how does
it use them? If I change some entry from "1" to "2" does Linux code
behave differently?


Best regards,
Krzysztof