Subject: Re: LANCE (Am7990) DMA
To: None <,>
From: Michael C. Richardson <>
List: tech-net
Date: 10/11/1998 13:35:14
>>>>> "Matthias" == Matthias Drochner <> writes:
    Matthias> You should make sure that the common code does compile
    Matthias> even if the platform doesn't implement the bus_dma interface.

    Matthias> Perhaps some words to the code structure which got one more
    Matthias> dimension since I split the am7990 and am79900 code:
    Matthias> am7990 is the old LANCE chip with 16-bit descriptors (and
    Matthias> 24-bit addressing capability). This driver part is used by all
  One thing that confused me about the 7990 stuff. When they are present on
VME/obio sun3/sparc'en, I know that they do DVMA. As far I can tell, they
use a rather small buffer of DVMA. (On sbus, there is an lebuffer, which
I assume they are restricted to.)

    Matthias> So the "direct DMA" capability should be orthogonal to the
    Matthias> existing features. This looks quite like a challenge, but it is
    Matthias> certainly worth a try.


   :!mcr!:            |  Network and security consulting/contract programming
   Michael Richardson |         Firewalls, TCP/IP and Unix administration
	ON HUMILITY: To err is human, to moo bovine.