Messages in this thread | | | Date | Wed, 03 Feb 2010 19:21:23 -0800 (PST) | Subject | Re: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg API description | From | David Miller <> |
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From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Date: Thu, 4 Feb 2010 12:13:22 +0900
> This adds the description of the following eight function: > > dma_sync_single_for_cpu > pci_dma_sync_single_for_cpuvoid ^^^^
That "void" is probably some cut and paste error :-)
> dma_sync_single_for_device > pci_dma_sync_single_for_device > dma_sync_sg_for_cpu > pci_dma_sync_sg_for_cpu > dma_sync_sg_for_device > pci_dma_sync_sg_for_device > > It was unclear that the API permits a partial sync (some network > drivers already do though). I made it clear that the sync_single API > can do a partial sync but the sync_sg API can't. > > We could do a partial sync with the sync_sg too, however, it's > difficult for driver writers to correctly use the sync_sg API for a > partial sync since the scatterlists passed in to the mapping API can > be modified. It's unlikely that driver writers want to do a partial > sync with the sync_sg API (because the sync_sg API are usually used > for block drivers). So I think that it's better to forbid a partial > sync with the sync_sg API. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: David S. Miller <davem@davemloft.net>
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