[vortex] 3c905C for a linux router

Donald Becker becker@scyld.com
Fri Nov 8 12:16:00 2002


On Fri, 8 Nov 2002, Bogdan Costescu wrote:
> On Fri, 8 Nov 2002, Ralph Doncaster wrote:
> 
> > The other thing I'd like to be able to do is rx interrupt mitigation
> > like the Tulip 21143.  The driver only seems to support tx interrupt
> > mitigation though.  Is there another driver I can use?
> 
> No, this is a hardware limitation. The 3Com design does not include Rx 
> interrupt mitigation. The only solution is software, using something like 
> the recently introduced NAPI; however, to use it efficiently the driver 
> has to be modified and to my knowledge there is no such driver yet. It's 
> on my list of things to add to the 3c59x driver, but recently this list 
> just grows because I can't find time...

Just to make this clear:
 It's only an hour or two of writing to add the NAPI code.
 It's a week or two of testing to see if the code works as designed
    with the different network adapters and work loads
 It's about a 1.5 years to decide if the NAPI structure is the right one.
    (NAPI is a change where people are doing measurement and analysis,
    unlike many other changes which are made just because they looked good
    to the author.)

-- 
Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Scyld Beowulf cluster system
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