Hello, On 18/05/17 13:23, Robin Murphy wrote: > The IOMMU-backed DMA API support has now been in place for a while and > proven stable, so there's no real need to keep most of Juno's SMMUs > disabled. The USB, HDLCDs, and CoreSight ETR all just need to map RAM > buffers for DMA - enabling their SMMUs obviates CPU bounce buffering for > USB's streaming DMA to the upper memory bank, and lets the other two > allocate their relatively large coherent buffers without pressuring CMA. > > Some more software work is still needed for the DMA-330 and PCIe before > those can accommodate SMMU translation correctly in all cases, so we > leave those alone for now. Out of curiosity, what is missing for DMA-330? I can use dmatest over SMMU on my juno-r1 by enabling the node, but I don't have any complex workload yet. Guest pass-through is really unreliable and I'm trying to figure out why. Thanks, Jean -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
