Re: [PATCH] arm64: dts: mediatek: mt8188: Fix IOMMU device for rdma0

["Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>]

Hi Chen-Yu,

On Tue, 2025-04-08 at 17:23 +0800, Chen-Yu Tsai wrote:
> 
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> 
> Based on the comments in the MT8188 IOMMU binding header, the rdma0
> device specifies the wrong IOMMU device for the IOMMU port it is
> tied to:
> 
>     This SoC have two MM IOMMU HWs, this is the connected
> information:
>     iommu-vdo: larb0/2/5/9/10/11A/11C/13/16B/17B/19/21
>     iommu-vpp: larb1/3/4/6/7/11B/12/14/15/16A/17A/23/27
> 
> rdma0's endpoint is M4U_PORT_L1_DISP_RDMA0 (on larb1), which should
> use
> iommu-vpp, but it is currently tied to iommu-vdo.
> 
> Somehow this went undetected until recently in Linux v6.15-rc1 with
> some
> IOMMU subsystem framework changes that caused the IOMMU to no longer
> work. The IOMMU would fail to probe if any devices associated with it
> could not be successfully attached. Prior to these changes, only the
> end device would be left without an IOMMU attached.
> 
> Fixes: 7075b21d1a8e ("arm64: dts: mediatek: mt8188: Add display nodes
> for vdosys0")
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>

Thanks for your fix patch.

Reviewed-by: Jason-JH Lin <jason-jh.lin@mediatek.com>

Regards,
Jason-JH Lin