On Monday 22 December 2014 16:40:43 Murali Karicheri wrote: > >> +++ b/arch/arm/mm/dma-mapping.c > >> @@ -2052,9 +2052,10 @@ void arch_setup_dma_ops(struct device *dev, u64 > >> dma_base, u64 size, > >> struct iommu_ops *iommu, bool coherent) > >> { > >> struct dma_map_ops *dma_ops; > >> + u64 temp_size = min((*(dev->dma_mask) + 1), size); > >> > >> dev->archdata.dma_coherent = coherent; > >> - if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) > >> + if (arm_setup_iommu_dma_ops(dev, dma_base, temp_size, iommu)) > >> > >> If you agree, I will post v1 of the patch with these updates. Let me > >> know. I did some basic tests on Keystone with these changes and it works > >> fine. > > > > It's not exactly what I meant. My main point was that we need to limit > > dev->dma_mask to (size-1) here, but you are not touching that. > > if you mean overriding the dev->dma_mask to min((*dev->dma_mask), > size-1), then I am getting the error "Coherent DMA mask 0x7fffffff (pfn > 0x780000-0x800000) covers a smaller range of system memory than the DMA > zone pfn 0x0-0x880000) when the devices on Keystone tries to set the dma > mask. Something wrong and I need to look into the code. Right, it sounds like the offset was applied incorrectly at some point. What are the DMA zone size and the phys-offset? Arnd -- 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