On Fri, 2013-01-04 at 17:10 +0100, Thomas Petazzoni wrote: > Dear Lubomir Rintel, > > On Thu, 27 Dec 2012 20:23:48 +0100, Lubomir Rintel wrote: > > > dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma, > > MV_XOR_TEST_SIZE, DMA_FROM_DEVICE); > > + dma_unmap_single(dma_chan->device->dev, dest_dma, MV_XOR_TEST_SIZE, > > + DMA_FROM_DEVICE); > > I would assume that dma_unmap_single() implies a > dma_sync_single_for_cpu() since you're unmapping the DMA buffer. So if > you use dma_unmap_single(), I think you can remove the call to > dma_sync_single_for_cpu().
Yes, it indeed seems to be the case (comment for arm_dma_unmap_page(): "After this call, reads by the CPU to the buffer are guaranteed to see whatever the device wrote there.". > > dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma, > > PAGE_SIZE, DMA_FROM_DEVICE); > > + dma_unmap_page(dma_chan->device->dev, dest_dma, PAGE_SIZE, > > + DMA_FROM_DEVICE); > > Ditto. > > Also, the mv_xor_memcpy_self_test() function not only dma_map_single() > the destination buffer, but also the source buffer. So presumably, the > source buffer should also be dma_unmap_single()'d. > > And for the mv_xor_xor_self_test() function, multiple source buffers > are dma_map_page()'d, so they should all be dma_unmap_page()'d I guess, > not only the destination buffer. Those get released by the mv_xor_run_tx_complete_actions() callback. I will follow up with an updated patch. Regards, Lubo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
