On Tue, Jun 22, 2010 at 03:30:08PM +0900, FUJITA Tomonori wrote: ... > > I don't see any harm in letting drivers know whether we can support > > consistent DMA allocs for a given struct device or not though, even if > > the micro-optimization is marginal at best. > > I'm happier with exporting less DMA APIs to drivers because looks like > new original ways to use the APIs wrongly can be always invented. Agree. ... > There are architectures that need to turn off the CPU cache for > coherent memory, I can't find none of them that see if an address is > coherent or not in dma_is_consistent(). parisc "knows" primarily based on chipset and then checks CPU model. We hook in the correct dma_ops early in boot before any device drivers are probed. hth, grant -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
