Re: [PATCH 02/22] dt-bindings: media: qcom,sm8550-iris: Allow IOVA reservation memory-region

[Dmitry Baryshkov]

On Fri, Aug 07, 2026 at 01:54:46PM +0530, Vikash Garodia wrote:
> From: Daniel J Blueman <daniel@xxxxxxxxx>
> 
> Non-pixel stream IDs should not allocate IOVA space from the 0 to 600MB
> restricted region, as this region is reserved exclusively for secure
> non-pixel.
> 
> In addition to the firmware-loaded codec carveout, Iris platforms need
> to declare an IOMMU IOVA reservation (a reserved-memory node with
> iommu-addresses) to keep DMA away from restricted IOVA range.
> 
> Permit a second memory-region phandle for this purpose, and describe
> the meaning of each entry so the ordering is unambiguous.
> 
> Fixes: 9065340ac04d ("arm64: dts: qcom: x1e80100: Add IRIS video codec")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Daniel J Blueman <daniel@xxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/media/qcom,sm8550-iris.yaml | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/media/qcom,sm8550-iris.yaml b/Documentation/devicetree/bindings/media/qcom,sm8550-iris.yaml
> index 0400ca1bff05dcef6b742c3fbf77e38adca9f280..7dff7293fd5c834b0ea617ece87ffbf0d40e821a 100644
> --- a/Documentation/devicetree/bindings/media/qcom,sm8550-iris.yaml
> +++ b/Documentation/devicetree/bindings/media/qcom,sm8550-iris.yaml
> @@ -84,7 +84,10 @@ properties:
>    dma-coherent: true
>  
>    memory-region:
> -    maxItems: 1
> +    minItems: 1
> +    items:
> +      - description: Firmware-loaded codec carveout
> +      - description: IOMMU IOVA reservation region

And how does it work if there is no firmware carveout?

-- 
With best wishes
Dmitry