On Mon, Jan 16, 2023 at 09:13:12PM +0530, Bhupesh Sharma wrote: > On Mon, 16 Jan 2023 at 13:23, Krzysztof Kozlowski > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > > On 15/01/2023 22:33, Bhupesh Sharma wrote: > > > On Sun, 15 Jan 2023 at 20:57, Krzysztof Kozlowski > > > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > >> > > >> On 13/01/2023 21:10, Bhupesh Sharma wrote: > > >>> Fix the following '#address-cells' & '#size-cells' related > > >>> dt-binding error: > > >>> > > >>> $ make dtbs_check > > >>> > > >>> From schema: Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml > > >>> arch/arm64/boot/dts/qcom/sm4250-oneplus-billie2.dtb: geniqup@4ac0000: > > >>> #address-cells:0:0: 2 was expected > > >>> From schema: Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml > > >> > > >> Don't we want rather to unify the soc address range? > > > > > > Well, the assumption in the original dt-bindings was that every reg > > > variable is 4 * u32 wide (as most new qcom SoCs set #address- and > > > #size-cells to <2>). However, that is not the case for all of the > > > SoCs. > > > > Hm, which device of that SoC cannot be used with address/size cells 2? > > As noted in the git log already the geniqup on sm6115 / sm4250 cannot > be used with address/size cells 2 (See: > https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/qcom/sm6115.dtsi#L795) > I'm not able to find the reasoning you're referring to. We do have cells of 2 for these nodes on all other platforms. If there is a specific problem, that can be documented and you can probably use ranges to reduce keep the cells of 1 in the geni wrappers. The reason why we have cells = 2 on most platforms is because the SMMU reports that it's capable of more address bits than the buses will handle. So without cells = 2, we can't describe dma-ranges appropriately and you get page faults due to truncated addresses on the bus when the iommu iova has been picking addresses for you. Regards, Bjorn > > > So, ideally we shouldn't set the "#address-cells" and "#size-cells": > > > as const: 2 in the bindings. > > > > > > See as an example: > > > https://www.kernel.org/doc/Documentation/devicetree/bindings/usb/usb-device.yaml > > > > > > How USB device - so entirely different device, not MMIO! - is related here? > > > > Best regards, > > Krzysztof > >
