>>>>> "Jeff" == Jeff Garzik <jgarzik@xxxxxxxxx> writes:
Jeff> Peter Chubb wrote:
>> With the current NS83820 driver and IP stack implementation, the
>> IA64 kernel spends 99.9% of its time in the unaligned access trap
>> handler when the network starts getting busy. When I raised this
>> issue before, the idea of realigning the skbuf data in the driver
>> was scouted; therefore I submit this patch for your approval. It
>> makes the driver usable, and doesn't seem to affect anything else.
Jeff> More likely, you need to play around with ns83820.c's
Jeff> skb_reserve() code, in rx_refill():
Unfortunately the dp83820 won't dma to anything other than a 64-bit
aligned packet. See table 3-2:
offset tag description
0004h bufptr 32- or 64- bit pointer to the first fragment
or buffer. In transmit descriptors the buffer
can begin on any byte boundary. In receive
descriptors, the buffer must be aligned on
a 64-bit boundary.
--
Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au
The technical we do immediately, the political takes *forever*
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