Messages in this thread | | | Date | Fri, 4 Jan 2013 17:10:33 +0100 | From | Thomas Petazzoni <> | Subject | Re: [PATCH 2/2] dma: mv_xor: do not sync the DMA buffer after being deallocated |
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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().
> 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.
Does that make sense?
Thanks,
Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
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