Paul Mundt wrote: > On Wed, Jun 16, 2010 at 08:53:57PM -0700, Michael Chan wrote: > > If sync_single is not defined, that means the CPU has a consistent > > view of next_rx_buf and so it makes sense to prefetch it. > > > Except that's not a valid assertion, there are platforms that > implement > it for sanity checks yet still have consistent DMA. You are making > inherently non-portable assumptions for a PCI driver, which is a good > example of why drivers should never be side-stepping the API > in the first > place. If you want to have a micro-optimization for the consistent DMA > case, you can check dma_is_consistent(), which is part of the API and > will be variable on certain platform configurations (ie, some may be > consistent with PCI but not on other busses, etc.) > > Thanks for the tip. I didn't know about the dma_is_consistent() API. I'll use this to fix it then. -- 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
