On Wed, 2010-02-17 at 11:23 +0100, Oliver Neukum wrote: > > The request a low-level driver does is all or nothing. Either DMA > issues have to be handled by that driver alone, or a finer-grained > description of the DMA requirements is needed. A fix using the latter > approach is being worked on. Well, that's what I'm trying to understand. IE. It's a pretty strong rule ... don't do CPU accesses between dma_map and unmap. So it's all in driver land at that stage. I'm not sure how the DMA requirements get into the picture here. IE. That rule is globally true. It's not going to hurt just non-coherent archs, it's going to hurt anybody using swiotlb too... So I don't see you need more info about the DMA requirements, but maybe I did miss something :-) Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
