Hi, everybody: How do we deal with this problem? I updated the kernel to the latest and the problem still persists. make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -j24 dtbs 2>err.txt vim err.txt arch/arm64/boot/dts/qcom/ipq6018.dtsi:185.3-14: Warning (dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) arch/arm64/boot/dts/qcom/ipq6018.dtsi:185.3-14: Warning (dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) On 2020/10/26 10:21, Leizhen (ThunderTown) wrote: > > > On 2020/10/23 15:17, Arnd Bergmann wrote: >> On Sun, Oct 18, 2020 at 4:10 AM Leizhen (ThunderTown) >> <thunder.leizhen@xxxxxxxxxx> wrote: >>> On 2020/10/17 3:27, Florian Fainelli wrote: >>>> On 10/16/20 11:23 AM, Arnd Bergmann wrote: >>>>> On Fri, Oct 16, 2020 at 6:48 PM Florian Fainelli <f.fainelli@xxxxxxxxx> wrote: >>>>>> On 10/16/20 4:01 AM, Arnd Bergmann wrote: >>>>>>> On Fri, Oct 16, 2020 at 11:09 AM Zhen Lei <thunder.leizhen@xxxxxxxxxx> wrote: >>>>>>>> >>>>>>>> Suggested-by: Arnd Bergmann <arnd@xxxxxxxx> >>>>>>>> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> >>>>>>> >>>>>>> Acked-by: Arnd Bergmann <arnd@xxxxxxxx> >>>>>>> >>>>>>> I see that at least the 'bcd' and 'xhci' devices in fact try to >>>>>>> use 64-bit DMA. It would be good to test this on actual >>>>>>> hardware to ensure that it works correctly when this is enabled. >>>>>>> >>>>>>> Ideally avoiding the swiotlb bounce buffering should only >>>>>>> make it faster here, but there are many chips on which >>>>>>> 64-bit DMA is broken in some form. >>>>>> >>>>>> Is this change really an improvement though? This 'usb' pseudo bus node >>>>>> could just keep being defined with #address-cells = <1> and #size-cells >>>>>> = <1> so as to satisfy the 'reg' definition however we could just adjust >>>>>> dma-ranges to indicate full 64-bit addressing capability. Would not that >>>>>> work? >>>>> >>>>> When #address-cells is '1', you cannot specify dma-ranges that >>>>> go beyond a 32-bit address range. >>>> >>>> Would not it be enough to remove the 'dma-ranges' property though? Sorry >>>> for being slow here. >>> >>> Remove the 'dma-ranges' property should also work. After all, it is equivalent >>> to the original empty dma-ranges scheme. In addition, since the IOMMU nodes are >>> defined, it should be enabled. >> >> Are you sure? I was expecting the IOMMU not to get used here since >> the devices do contain list an 'iommus' property. > > OK,If the SMMU maybe disabled, then your proposal is necessary. > >> >> Arnd >> >> . >>