On Thu, Oct 18, 2012 at 10:59:56AM +0100, Alan Cox wrote: > > > + > > > skb_headlen(skb), > > > + DMA_TO_DEVICE); > > > + desc[frag].addr_lo = dma_addr & > > > 0xFFFFFFFF; > > > + desc[frag].addr_hi = dma_addr >> 32; > > > > Maybe use macros defined in kernel.h instead: > > > > desc[frag].addr_lo = lower_32_bits(dma_addr); > > desc[frag].addr_hi = upper_32_bits(dma_addr); > > > > A few more instances below. > > This is actually important because >> 32 of a 32bit value is undefined in > C. The compiler is free to do what it likes with this. While the results > are usually sane some architectures do generate the equivalent of > > x >> (n % wordsize); > > Alan
Thanks for the comments both. I'll send an updated patch this evening. The intention is to eventually store this value as a dma_addr_t anyway, but some more work needs to be done to copy the address correctly to the desc ring. Cheers, Mark -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
