Re: [PATCH] arm64: dts: fsd: Change the reg properties from 64-bit to 32-bit

[Arnd Bergmann]

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