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

[Bryan O'Donoghue]

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