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

Dmitry Baryshkov
2025-07-04T16:45:32Z

On Fri, Jul 04, 2025 at 09:23:06AM +0100, Bryan O'Donoghue wrote:
> On 03/07/2025 22:23, Dmitry Baryshkov wrote:
> > > I still give my RB for the series.
> > >
> > > To me the only question is should it be applied to sm8550 or to new SoCs
> > > from now on, sa8775p, x1e and derivatives.
> > I think we need to apply it to_all_ SoCs, maybe starting from MSM8x26
> > and MSM8x16. Likewise, we need to think bout secure buffers usecase. And
> > once we do that, we will realize that it also changes the ABI for all
> > SoCs that support either Venus or Iris.
>
> I think a dts change is a non-starter as its an ABI break.
>
> So if ABI break is out and reworking future dts to allow for a new device is
> out, then some API change is needed to allow the driver to stop the kernel
> automatically setting up the IOMMUs, create the new device as a platform
> device not dependent on DT change and have the probe() of the relevant
> drivers setup their own IOMMU extents based on - probably indexes we have in
> the driver configuration parameters.

What about instead:

- keep IOMMU entries as is
- Add iommu-maps, mapping the non-pixel SID
- In future expand iommu-maps, describing the secure contexts?

>
> ---
> bod

--
With best wishes
Dmitry