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Date:   Wed, 16 Nov 2022 12:16:49 +0100
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Vivek Yadav" <vivek.2311@samsung.com>, rcsekar@samsung.com,
        krzysztof.kozlowski+dt@linaro.org,
        "Wolfgang Grandegger" <wg@grandegger.com>,
        "Marc Kleine-Budde" <mkl@pengutronix.de>,
        "David S . Miller" <davem@davemloft.net>,
        "Eric Dumazet" <edumazet@google.com>,
        "Jakub Kicinski" <kuba@kernel.org>,
        "Paolo Abeni" <pabeni@redhat.com>, pankaj.dubey@samsung.com,
        ravi.patel@samsung.com, "Alim Akhtar" <alim.akhtar@samsung.com>,
        linux-fsd@tesla.com, "Rob Herring" <robh+dt@kernel.org>
Cc:     linux-can@vger.kernel.org, Netdev <netdev@vger.kernel.org>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
        aswani.reddy@samsung.com, sriranjani.p@samsung.com,
        ajaykumar.rs@samsung.com
Subject: Re: [PATCH] arm64: dts: fsd: Change the reg properties from 64-bit to 32-bit
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On Wed, Nov 16, 2022, at 10:12, Vivek Yadav wrote:
> Change the reg properties from 64-bit to 32-bit for all IPs, as none of
> the nodes are above 32-bit range in the fsd SoC.
>
> Since dma-ranges length does not fit into 32-bit size, keep it 64-bit
> and move it to specific node where it is used instead of SoC section.

I don't think that works, the dma-ranges property is part of the
bus, not a particular device:

 		mdma0: dma-controller@10100000 {
 			compatible = "arm,pl330", "arm,primecell";
-			reg = <0x0 0x10100000 0x0 0x1000>;
+			reg = <0x10100000 0x1000>;
 			interrupts = <GIC_SPI 424 IRQ_TYPE_LEVEL_HIGH>;
 			#dma-cells = <1>;
 			clocks = <&clock_imem IMEM_DMA0_IPCLKPORT_ACLK>;
 			clock-names = "apb_pclk";
 			iommus = <&smmu_imem 0x800 0x0>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			dma-ranges = <0x0 0x0 0x0 0x10 0x0>;
 		};

Since the dma-controller has no children, I don't see how this has
any effect. Also, translating a 36-bit address into a 32-bit
address just means it gets truncated anyway, so there is no
point in making it appear to have a larger address range.

      Arnd