On Wed, 01 Aug 2007 15:56:48 +0800, Songmao Tian <tiansm@xxxxxxxxxx> wrote: > The problem is clear: > 1. dma_alloc_noncoherent() return a non-cached address, and > virt_to_page() need a cached logical addr (Have I named it right?) > 2. mmaped dam buffer should be non-cached. > > We have a ugly patch, but we want to solve the problem cleanly, so can > anyone show me the way? virt_to_page() is used in many place in mm so making it robust might affect performance. IMHO virt_to_page() seems too low-level as DMA API. If something like dma_virt_to_page(dev, cpu_addr) which can take a cpu address returned by dma_xxx APIs was defined, MIPS can implement it appropriately. And then pgprot_noncached issues still exist... --- Atsushi Nemoto
