[vortex] cyclone: howto pausing during an upload

[Donald Becker]

On Wed, 20 Sep 2000, Joel Hollingsworth wrote:

> Does anyone know of a method to force the cyclone to 
> upload a single fragment (maybe just the header), 
> generate an interrupt, allow the driver to handle
> the interrupt (i.e. reset the address for the next
> fragment), and then continue on with the upload 
> of the second fragment. 
> 
> Yep, I would like to prefetch the header and then
> use the header before fetching the packet data.

If this is for a specific project, you should look at the SMSC EPIC chip
that explicitly allows using the chip in this manner.

If you plan to introduce a general mechanism for multiple chips, give up.
Most chips are really unhappy about restarting when they run out of
descriptors/buffers before the whole packet is received.

I suspect that you can get a specific 3Com chip model to work OK in this
mode, but you shouldn't count on your driver being portable to other chips.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Beowulf-II Cluster Distribution
Annapolis MD 21403