Re: Ti PB -- nervous breakdown

[Peter Cordes <peter@llama.nslug.ns.ca>]

On Mon, Mar 12, 2001 at 09:39:01AM +0100, Christoph Ewering wrote:
> Benjamin Herrenschmidt schrieb:
> > The Ethernet PHY is, I guess, different and not yet properly supported. Can
> > you tell me what the ethernet driver says during boot about the type of PHY ?
> 
> Have to look for it in the afternoon. But look at my other mails I told
> Timothy that this is not just a wrong reported connection speed, I need
> 20-30 minutes to copy the 2.4.2-kernel-source form the Pismo to the TiPB
> both running linux.

 I think this makes sense :)  If the Titanium is in full duplex mode, but
the Pismo is set up to use half duplex, you will get a huge number of
collisions.  (full duplex = send and receive at the same time is ok.  half
duplex = wait for the other side to stop sending before we send.  If the
half duplex end sends a frame, then sends another frame right behind it,
and the full duplex side finishes processing the first frame and sends an
ACK while the second frame from the half duplex machine is being sent, the
half duplex machine will interpret this as a collision, and back off sending.)

 To see if this is happening, run  ifconfig, and note the number of
collisions reported.  It should be really high on the machine that says it
is using half duplex.

-- 
#define X(x,y) x##y
Peter Cordes ;  e-mail: X(peter@llama.nslug. , ns.ca)

"The gods confound the man who first found out how to distinguish the hours!
 Confound him, too, who in this place set up a sundial, to cut and hack
 my day so wretchedly into small pieces!" -- Plautus, 200 BCE