> I'm doing a strange thing and attempting to insert a new buffer > into the receive ring of a network adapter. I believe that my problem > comes in the form of incorrectly setting up DMA. I have looked at the > documentation on DMA transfers and have found nothing wrong with what > I'm doing. > > What happens? Once the network adapter gets around to > dropping a packet > into my buffer, the DMA transfer acts like it works, except > that buffer > has not been altered in any way. I actually check the buffer in the > device driver interrupt code (as soon as the transfer is > supposed to be > complete). My guess is that your modifications to the descriptor are never seen by the PRO/1000 device. Descriptors are fetched in blocks when possible and cached, and there is no way to invalidate a descriptor that has been handed over to hardware "ownership" by the write to RDT. I don't think there is a safe way to mess with descriptors or buffers after the write to RDT short of a global reset of the device. -- Chris - : 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
