Date:   Mon, 30 Jan 2023 16:50:32 -0600
From:   Rob Herring <robh@kernel.org>
To:     Alexandre Bailon <abailon@baylibre.com>
Cc:     yong.wu@mediatek.com, joro@8bytes.org, will@kernel.org,
        robin.murphy@arm.com, matthias.bgg@gmail.com,
        krzysztof.kozlowski@linaro.org, iommu@lists.linux.dev,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org
Subject: Re: [PATCH 3/3] dt-bindings: iommu: memory: Use unmanaged iommu
 domain for the APU
Message-ID: <20230130225032.GA3667757-robh@kernel.org>
References: <20230130102722.133271-1-abailon@baylibre.com>
 <20230130102722.133271-4-abailon@baylibre.com>
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On Mon, Jan 30, 2023 at 11:27:22AM +0100, Alexandre Bailon wrote:
> This updates the iommu id to use unmanaged iommu domain for the APU.
> This is required by remoteproc to use the iommu.

Explain how a mixture of DTs with or without this value changed would 
work with kernels with or without support for unmanaged domains? Looks 
like a compatibility problem to me.

> 
> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
> ---
>  include/dt-bindings/memory/mediatek,mt8365-larb-port.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/dt-bindings/memory/mediatek,mt8365-larb-port.h b/include/dt-bindings/memory/mediatek,mt8365-larb-port.h
> index 56d5a5dd519e7..86d82a8f6017d 100644
> --- a/include/dt-bindings/memory/mediatek,mt8365-larb-port.h
> +++ b/include/dt-bindings/memory/mediatek,mt8365-larb-port.h
> @@ -24,8 +24,8 @@
>  #define M4U_PORT_MDP_WROT0		MTK_M4U_ID(M4U_LARB0_ID, 7)
>  #define M4U_PORT_MDP_RDMA1		MTK_M4U_ID(M4U_LARB0_ID, 8)
>  #define M4U_PORT_DISP_FAKE0		MTK_M4U_ID(M4U_LARB0_ID, 9)
> -#define M4U_PORT_APU_READ		MTK_M4U_ID(M4U_LARB0_ID, 10)
> -#define M4U_PORT_APU_WRITE		MTK_M4U_ID(M4U_LARB0_ID, 11)
> +#define M4U_PORT_APU_READ		MTK_M4U_UNMANAGED_ID(M4U_LARB0_ID, 10)
> +#define M4U_PORT_APU_WRITE		MTK_M4U_UNMANAGED_ID(M4U_LARB0_ID, 11)
>  
>  /* larb1 */
>  #define M4U_PORT_VENC_RCPU		MTK_M4U_ID(M4U_LARB1_ID, 0)
> -- 
> 2.38.2
>