Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: build_skb() and data corruption | Date | Tue, 14 Jan 2014 16:51:34 +0100 |
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On Tuesday 14 January 2014, Jonas Jensen wrote: > Thanks for the replies, you led me to a new solution, > > > I now think build_skb() is not the right choice, my motivation for > using it in the first place, that I thought it meant getting away with > not copying memory. > > build_skb() is replaced by netdev_alloc_skb_ip_align() and memcpy() > (derived from drivers/net/ethernet/realtek/r8169.c). > > Read errors are gone, even without syncing DMA. Is it a good idea to > do it anyway, i.e. leave calls to dma_sync_single_* in?
The calls to dma_sync_single_* in the moxart_rx() function are needed. The call to arm_dma_ops.sync_single_for_device() in moxart_mac_setup_desc_ring() is wrong, because the buffer is already owned by the device at that point (just after dma_map_single), and because you should use the official dma_* api rather than using the arm_dma_ops struct.
Arnd
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