Subject: Re: OSS lkm for NeoMagic (was: Re: a.out and -current)
To: Nathan J. Williams <nathanw@MIT.EDU>
From: Lennart Augustsson <>
List: current-users
Date: 02/06/2000 12:01:47
"Nathan J. Williams" wrote:

> <jonathan@DSG.Stanford.EDU> (Jonathan Stone) writes:
> > But... the neomagic is an ac97 device at heat. rather than porting the
> > OSS driver, woudln't it make more sense to engineer a native netbsd
> > driver, usign our ac'97 support, and the info in the OSS or linux
> > 2.2.13 neomagic drivers?
> This would be nice, yes.
> I'd like to point out that AC'97 is a spec for the *back-end* A/D
> engine and the interface that the actual audio chip uses to talk to
> it. Thus, while we do have some generic AC'97 code, it's not as much
> of a leg up as people sometimes seem to think - you still have to deal
> with setting up the front-end chip: interrupts, DMA, programming the
> sample rate converter, and other front-end-specific goo. The AC'97
> support lets you get the mixer code for cheap, but not much else.

Exactly.  It probably cuts down the code in a driver by half, but the half
that's cut away is the one that requires least thought to write.  So writing
a driver with AC97 is still non-trivial.


        -- Lennart