On Wed, 21 May 2003 18:45:53 +0100, Rask Ingemann Lambertsen wrote
> All of the above assumed that you use PIO transfers. With a DMA
> device, you'll need to manage the pointers yourself on the receive
> side when dealing with the chunks. Something like:
>
> skb = dev_alloc_skb (4K + alignment);
> skb_reserve (skb, alignment);
> dma_pointer = pci_map_single (pdev, skb->head, 4K, PCI_DMA_FROMDEVICE);
> /* await completion of DMA */
> skb_put (skb, length_of_whole_packet);
> pci_unmap_single (pdev, dma_pointer, skb->head, 4K, PCI_DMA_FROMDEVICE);
Second try, hopefully correct this time:
skb = dev_alloc_skb (4K + alignment);
skb_reserve (skb, alignment);
dma_pointer = pci_map_single (pdev, skb->tail, 4K, PCI_DMA_FROMDEVICE);
/* await completion of DMA */
pci_unmap_single (pdev, dma_pointer, 4K, PCI_DMA_FROMDEVICE);
skb_put (skb, length_of_whole_packet);
(Note: skb->tail instead of skb->head!)
-- Regards, Rask Ingemann Lambertsen- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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