On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote: > This way we have one central definition of it, and user can select it as > needed. Note that we also add a second ARCH_HAS_SWIOTLB symbol to > indicate the architecture supports swiotlb at all, so that we can still > make the usage optional for a few architectures that want this feature > to be user selectable. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by default, which probably isn't a good idea - ARM pre-dates the dma_length parameter in scatterlists, and I don't think all code is guaranteed to do the right thing if this is enabled. For example, arch/arm/mach-rpc/dma.c doesn't use the dma_length member of struct scatterlist. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up
