Subject: Re: ne driver in Netbsd-1.3/alpha
To: Wilko Bulte <wilko@yedi.iaf.nl>
From: Andreas Johansson <ajo@wopr.campus.luth.se>
List: port-alpha
Date: 01/26/1998 00:02:05
On Sun, 25 Jan 1998, Wilko Bulte wrote:

> Quick question: is the 'ne' (NE1000/2000 driver) in NetBSD1.3
> supposed to work?

No, it doesn't work. I made a fix for it and submitted it as a send-pr,
but it was fixed in the wrong place so to speak. I never got around to fix
it "better" even though I know how to do it.

There are two problems. One is in the receiving of packets. The ip header
becomes unaligned to 32 bits since the ethernet header is not divisible by
four. This is simply overcome by moving the data pointer two steps ahead
in each mbuf.

The second problem is that sometimes (not often) packets are sent which
include several mbuf's where one of them (not the last) has uneven size.
This means that the next mbuf will be transferred from an uneven address,
while the 16 bit accesses to the isa bus requires aligned pointers on the
alpha. The driver should be changed to so it puts bytes together and
sends these with a 16 bit transfer whenever the mbuf data is unaligned.

/Andreas
--

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