Subject: Re: ifmedia on fxp: can ifmedia defeat NWAY and force 10baseT?
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-kern
Date: 10/27/1999 20:13:36
On Wed, 27 Oct 1999 19:21:45 -0700 
 Jonathan Stone <jonathan@DSG.Stanford.EDU> wrote:

 > I assume because that initiates an Nway cycle?
 > 
 > Looks like the driver is DTRT with the NIC speed, and the lights
 > suggest the NetGear hub is noticing link-fail, but the hub isnt
 > restarting NWay.  (Or maybe it is, but either times out or starts
 > too late?)
 > 
 > So, is it okay for the driver to force the NIC to start an NWAY cycle,
 > after the driver changes the advertized media (in the APAR or whatever
 > its called?)  The 802.3 text Matthias quoted seems like that'd be OK,
 > and to me it sounds more robust than what we do now. (Yes, better hubs
 > would be nice, but...)  Jason, does that sound okay to you?

I'll take a look at this later this week; I am facing similar issues
with 21143 support in the `tlp' driver (the 21143 has a built-in Nway
block, as well as MII support .. gack).

FWIW, the NIC driver won't have anything to do with this.  It will all
be handled by the PHY drivers.  No changes to the NIC drivers will be
necessary at all.

It's going to require some fairly significant changes to the MII code,
I think.  However, it will also make the code a bit smaller, because
every PHY driver will effectively use the same code to do media selection
(more so than they do already).

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