> > You are assuming the PCI memory space is prefetchable( no > > side effect) for DMA. > > Is it possible that DMA is from non-prefetchable memory space? > > This should be a safe assumption for this driver. Remember, this > driver just does offload memcpy, from one region to another. So the > PCI memory that you are reading from should be just a buffer of data, > and there should be side-effect of reading it. > > However, I would like to see a comment at the top of the file warning > people that copying from PCI memory will result in prefetched reads.
How about FIFO RAM case? _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev