Re: [PATCH v5 5/5] arm64: dts: broadcom: bcm2712: Add GPU IOMMU and IOMMU cache nodes

[Daniel Drake]

On 09/09/2026 21:08, Daniel Drake wrote:
> Define the IOMMU and IOMMUC nodes for the Broadcom BCM2712 SoC found in
> the Raspberry Pi 5. Enable use of the IOMMU for the graphics/display
> block.


> @@ -667,6 +680,7 @@ v3d: gpu@1002000000 {
>   
>   	vc4: gpu {
>   		compatible = "brcm,bcm2712-vc6";
> +		iommus = <&iommu4>;
>   	};
>   
>   	timer {
> @@ -701,5 +715,6 @@ hvs: hvs@107c580000 {
>   		interrupt-parent = <&disp_intr>;
>   		interrupts = <2>, <9>, <16>;
>   		interrupt-names = "ch0-eof", "ch1-eof", "ch2-eof";
> +		iommus = <&iommu4>;

Found some issues here: the iommus property needs to be added to the 
dt-bindings for this to be considered valid, and actually, it should not 
be added to the vc4 node (that is just a virtual node), only the hvs node.

But that setup triggers a warning from the iommu layer because the 
dma/iommu setup is established too late during vc4 device setup.

Working on it...