On Tue, Apr 05, 2016 at 12:45:08AM +0100, Al Viro wrote: > AFAICS, what we need there is simply > nr_pages = iov_iter_npages(iter); > alignment = iov_iter_alignment(iter); > if (alignment & (queue_dma_alignment(q) | q->dma_pad_mask)) > copy = true; > and I really wonder if we care about special-casing the situation when the > ends are not aligned to queue_virt_boundary(q). If we don't, we might as > well add queue_virt_boundary(q) to the mask we are checking. If we do, > it's not hard to add a variant that would calculate both the alignment and > alignment for internal boundaries...
I suspect this is the right thing to do. Care to send a patch to Jens?
