Re: [PATCH v3 0/5] Introduce "non-pixel" sub node within iris video node

Bryan O'Donoghue
2025-10-09T11:06:29Z

On 09/10/2025 11:45, Krzysztof Kozlowski wrote:
> On 09/10/2025 19:40, Vikash Garodia wrote:
>>
>> On 10/9/2025 2:41 PM, Krzysztof Kozlowski wrote:
>>> On 09/10/2025 17:38, Bryan O'Donoghue wrote:
>>>> On 09/10/2025 02:04, Krzysztof Kozlowski wrote:
>>>>>> The iommu description for this platform basically lacks the data that
>>>>>> _should_ be there -> FUNCTION_ID.
>>>>> No. The index tells that already.
>>>>
>>>> Hmm.
>>>>>> The rule is that the DT should really describe the hardware right ?
>>>>> It already does. Same as I wrote on IRC, DT already has all the
>>>>> information. Entry 0 has function ID-foo. Entry 1 has function ID-bar.
>>>>> Entry 2 has function ID-bar or whatever.
>>>>
>>>> That's the part I don't believe is true its a 1:Many relationship
>>>> between FUNCTION_ID:SIDs
>>>>
>>>> Let me check the docs...
>>>>
>>>> Here's the example I gave on IRC for lore
>>>>
>>>> SID 0x1940 maps to AC_VM_HLOS (Linux)
>>>> SID 0x1941 maps to AC_VM_CP_BITSTREAM - protected bitstream
>>>> SID 0x1945 maps to AC_WM_CP_BITSTREAM
>>>>
>>>
>>> I responded to this on IRC... Nothing proves here that 1:many cannot be
>>> done.
>>
>> Kaanapali already has 1:Many relationship for FUNCTION_ID:SIDs.
>
> Sun is a star. How is that related? I am not going to duplicate
> arguments from IRC, especially to that pointless argument. Read again
> discussion on IRC.
>
> Best regards,
> Krzysztof

But Krzysztof is it not the case DT should be a representation of the
real hardware and that this takes priority over established schema.

There seems to be no other reason to keep SID in the DT and FUNCTION_ID
in driver meta-data except the schema already says X.

There are as I count it, 189 TCU SID mappings for Hamoa.

So in the extreme case that means we have an iommu = <> for each of
those but then need a corresponding entry in a driver to map each SID to
its relevant FUNCTION_ID.

And do that over and over again for each new SoC.

OTOH if we extend the iommu to include FUNCTION_ID then only the DT
changes - with the iommu setup code changing once to accommodate it.

---
bod