> This function is called only for the PIO mode commands, so I doubt this is > necessary... That is true but there are platforms out there that issue disk level PIO commands via DMA (or can do so). Indeed the Cyrix MediaGX could do that in the 1990s but I never add support 8) So I think it makes sense to allocate the buffers DMA aligned, but it doesn't seem to explain the situation in this case and I think it would be helpful to know what platform and ATA driver is tripping this and wny they are the only people in the universe to have the problem. Alan