search for: dma_sync_single_range

...synchronise a single contiguous or scatter/gather mapping. All the parameters must be the same as those passed into the single mapping API. and mthca is *not* following this clear rule: it is trying to sync only a subrange of the mapping. Later on in the document, there is: void dma_sync_single_range(struct device *dev, dma_addr_t dma_handle, unsigned long offset, size_t size, enum dma_data_direction direction) does a partial sync. starting at offset and continuing for size. You must be careful to observe the cache alignment and width when doing anythi...