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

Bryan O'Donoghue
2025-10-09T08:38:10Z

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

The xls for these mappings runs to a few hundred lines.

Seems to me like a good argument - at least for the qcom iommus to add a
cell entry and then teach the generic iommu code about it.

---
bod