Subject: Re: LANCE (Am7990) DMA
To: None <thorpej@nas.nasa.gov>
From: Anders Magnusson <ragge@ludd.luth.se>
List: tech-net
Date: 10/07/1998 08:56:57
>
> FWIW... I just looked again... turns out that Ragge's "ln" driver for
> the VAXstation does NOT DMA into mbufs... I guess all he did was fix
> the initialization ordering that was apparently wrong for DEC LANCE
> implementations before (and, of course, the inlining of the register
> access).
>
Eh... it does. But I haven't checked it in; it sometimes got memory errors
on VS4000 and I haven't found out why. If someone have a VS2000 he probably
wants to use the DMA version if the machine must survive network load.
The DMA version is available at subzero.campus.luth.se:/users/ragge/if_ln.c
if someone wants to look at it.
Note: It only does DMA to, not from, mbufs. DEC requies that at least
100 bytes is sent from each buffer, so...
-- Ragge