On Tue, Dec 18, 2018 at 11:43:08AM -0700, Jason Gunthorpe wrote: > So the problem here is that on some arches > > sg_set_buf(sg, dma_coherent_buf, size) > p = sg_virt(sg); > assert(p == dma_coherent_buf);
dma allocations purely return a virtual address, you must never call virt_to_page or virt_to_phys on them, which sg_set_buf will do. On many architectures this will give your the wrong result as the coherent DMA address is a vmap or ioremap address.
