Subject: Re: Help enabling PCI ethernet card, tlp0
To: Steven M. Bellovin <smb@research.att.com>
From: David Laight <david@l8s.co.uk>
List: netbsd-users
Date: 12/16/2002 14:56:15
> That was my first thought, especially since I have a 10BaseT-only 
> Lucent "Residential Gateway", which is a clone of the Airport.  But a 
> check of Apple's Web page shows that the newer Airports do support 
> 100BaseT.

It is, of course, possible that they will only autonegotiate to
100BaseT but will not autodetect it.

I've also seen drivers that get in a mess when the interface is
rotated beweeen:
	10BaseT only	(eg 10M hub)
	100BaseT only	(eg 100M hub)
	10BaseT, 100BaseT autodetect	(some 10/100 split hubs)
	autonegotiate with only some options enabled (any driver
	    where someone has been playing with the PHY ANAR register).

Not least of the problems is that the 'globally defined' phy registers
don't tell you the mode that the interface is working in.  The driver
doesn't need to know whether it is 10BaseT or 100BaseT, but does
need to know whether FDX is enabled.  For sanities sake I would
only ever enable FDX if I could detect that it had been negotiated
between the two PHY, anything else is likely to lead to massive
packet loss under load.

	David

-- 
David Laight: david@l8s.co.uk