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

From: Robin Murphy
Date: Wed Nov 16 2022 - 07:39:35 EST


On 2022-11-16 11:16, Arnd Bergmann wrote:
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.

Yes, this is definitely bogus on both counts.

Thanks,
Robin.