[Resending with CC to affected parties] Hi, I would expect cache synchronization for DMA_TO_DEVICE and DMA_BIDIRECTIONAL when dma_map_single() is called, and for DMA_FROM_DEVICE and DMA_BIDIRECTIONAL when dma_unmap_single() is called. However, on some architechtures (at least avr32, blackfin, ...), cache synchronization only happens when dma_map_single() is called (and then irrespective of DMA direction). dma_unmap_single() is a no-op for these archs. See e.g. http://lxr.linux.no/#linux+v3.0.4/arch/avr32/include/asm/dma-mapping.h#L117 Isn't this a bug? (Please CC me in responses.) -- Arvid Brodin Enea Services Stockholm AB -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html