Lite5200 FEC Driver on linux 2.6 broken? (again)

roger blofeld blofeldus at yahoo.com
Wed Nov 17 08:28:13 EST 2004


--- Dale Farnsworth <dale at farnsworth.org> wrote:

> On Tue, Nov 16, 2004 at 10:26:09AM -0800, roger blofeld wrote:
> > Retransmissions from the lite5200 work OK now, but the occasional
> ACK
> > packet is sent from the lite5200 with a bad checksum causing
> > retransmissions. Perhaps another patch would fix this problem too?
> 
> I too have seen occasional errors, but I don't think it's a software
> issue.
> 
> -Dale
> 
One more clue to what is happening: Whenever a packet is transmitted
with a bad checksum, the tail end of the data is in error. For example,
a packet of 0x442 bytes (0x42 header, 0x400 data) is corrupt from byte
0x360 on. Corruption always happens at a multiple of 0x10 from the
start of the packet. If it is software, perhaps we don't wait long
enough for DMA completion, or DMA signals completion too soon? Or maybe
the buffer is re-used or stomped on? Seems like too large of a
corruption to be due to cache.
-roger


		
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