On 16/01/2019 07:49, Bjorn Andersson wrote: > DMA addresses for devices on the soc bus must be constrained to the 36 > address bits that the bus provides. When no IOMMU is present then this > is easy--DMA addresses are just physical addresses and physical > addresses are (by definition) within the address bits of the bus. When > an IOMMU is present, however, DMA addresses are virtual addresses. > Despite these addresses being virtual, however, they are still > constrained by the 36 address bits of the bus. > > Unless dma-ranges is specified, which causes bus_dma_mask to be set, DMA > allocations for devices on the platform_bus will use all 48 address bits > available by the ARM SMMU. Causing addresses to be truncated on the bus. > > This patch increases the #size-cells to 2, in order to be able to define > dma-ranges describe the 36 bit DMA capability of the bus, and bumps Seems like you changed your mind mid-sentence? :-) > While touching all reg properties, addresses are padded to 8 digits.
