Hi, I noticed using dma_mmap_coherent() on pages allocated via dma_alloc_coherent() results in a warning on x86:
map pfn RAM range req uncached-minus for [mem 0x21d500000-0x21d51ffff], got write-back which comes from arch/x86/mm/pat.c. Looking at the code, it seems that dma_mmap_coherent() blindly assumes that the pages are with pgprot_noncached(), but on x86, it's obviously not. Maybe some other archs have the same problem. How should we fix this? Defining a new pgprot_xxx(), and falling back to pgprot_noncached if undefined? Or is it just x86 and do it only there? thanks, Takashi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
