On Tue, 12 Mar 1996 22:17:19 -0500 (EST) 
 David Gilbert <dgilbert@jaywon.pci.on.ca> wrote:

 > 	However (oh no, they say), I'm getting bit abominally bad by
 > the 'ie0: DMA underrun' message.  If I try an FTP transfer (like when
 > you type 'dir'), I get a quick smattering of messages... and
 > eventually the pc will time out.
 > 
 > 	The nfs mount command went fine.  However, an ls -l of a
 > directory on the mounted drive is still producing these messages, and
 > it probably will until I get the machine to reboot.
 > 
 > 	Any help with the DMA underrun?

On my 4/260:

[ . . . ]
ie0: DMA underrun
ie0: DMA underrun
ie0: DMA underrun
[ . ad nauseum . ]

Some (I suspect) timing glitch in the ie driver causes this.  The 
on-wire manifestation is a garbled/incomplete ethernet frame.  Note that 
using DMA on the "si" driver makes it worse, but *only* for the obio ie.  
I've never seen these errors when using the following combinations:

	- VME ie, VME si
	- obio ie, obio sw (4/100)

Since my 4/260 is the NFS server (root/swap) for my MVME-147, my MVME-147 
frequently loses (which, I guess, is ok, since I haven't had any time to 
hack on it for quite a while.. :-/ ).

Note my hp300s and sun3s all recover Just Fine (after reporting an CRC 
and framing error ... all other machines on my network have LANCE 
ethernet interfaces :-).

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
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