Messages in this thread | | | Date | Fri, 24 May 2002 13:58:42 -0700 | From | William Jhun <> | Subject | Re: Possible discrepancy regarding streaming DMA mappings in DMA-mapping.txt? |
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On Fri, May 24, 2002 at 01:26:41PM -0700, David S. Miller wrote: > > I know what you're trying to do, but I'm going to tell you upfront > that this will make the existing case much more inefficient than > it needs to be.
Sorry, I'm not clear on this one. I was first proposing (for the short term, at least) to not change anything at all: all the existing implementations of pci_dma_sync_*(..., PCIDMA_TO_DEVICE) already do what is required: prepare the buffer to be DMAed from by the controller. Most drivers won't have to deal with this; most network drivers, for example, do a pci_map_*() on an skb passed down from the stack and subsequently pci_unmap_*() those buffers once transmitted, thus having no need for pci_dma_sync_*()... So I don't see how this makes anything else less efficient...
> > Please, add a new call to handle your case. Thanks.
Such a call would do what pci_dma_sync_*(..., PCIDMA_TO_DEVICE) already does (unless that is what you want - to have a new call just for the sake of clarity...).
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