Re: [PATCH v4 1/3] dt-bindings: media: qcom,qcm2290-venus: document shikra Iris compatible

[Dmitry Baryshkov]

On Tue, Jul 21, 2026 at 11:02:25PM +0530, Vikash Garodia wrote:
> Document the iris video accelerator used on shikra platforms by adding
> the qcom,shikra-iris compatible.
> 
> Although QCM2290 and shikra share the same video hardware and overall
> integration, their SMMU programming differs. QCM2290 exposes separate
> stream IDs for the video hardware and the Xtensa path, requiring two
> explicit IOMMU entries, whereas shikra uses a masked SMR to collapse
> equivalent stream IDs into a single mapping. Due to QCM2290’s SID layout
> and Xtensa isolation requirements, such SMR masking is not applicable on
> QCM2290 platforms.

This means that there are still two different streams, one for pixel and
one for non-pixel data. Stop using the mask and describe them
separately. One will go to the pixel node, another will go to the
non-pixel node. As you wrote, the hardware is the same as QCM2290, which
has two separate streams.

> Since shikra uses the same video hardware as QCM2290 and shares the same
> programming model and capabilities, it is added as a fallback compatible
> to qcom,qcm2290-venus, with conditional handling to allow either one or
> two IOMMU entries.
> Common schema is updated to accommodate the iova restriction of 600MB.
> VPU restricts usage of 600MB for specific streams, which could otherwise
> lead to device crash.
> 
> Reviewed-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>

-- 
With best wishes
Dmitry