Subject: Re: Various NetBSD kernel questions to help with port of FreeBSD "zaptel" drivers.
To: Ty Sarna <>
From: Thor Lancelot Simon <>
List: tech-kern
Date: 11/08/2004 11:35:53
On Mon, Nov 08, 2004 at 10:45:01AM -0500, Ty Sarna wrote:
> In article <> you write:
> > The cleanest way: make the actual lower-level drivers have softcs, and
> > make the upper layer into a pseudo-driver kind of like scsibus, usb,
> > audio, atabus, pcmcia, etc.
> Indeed, it seems to me like it would be especially nice if the upper
> layer *was* the "audio" driver, or an extended variant thereof.

Wow, I don't think so.  Telephony is seldom concerned with the content
of audio streams, and indeed one generally wants to keep them out of
main memory if at all possible (in software VoIP applications, it's
seldom possible, but that does not mean that one does not _want_ to
avoid hauling it into memory and working on it there...).

Generally, telephony is concerned with _where audio goes_, not
_what's in it_.  And it requires an interface for controlling where
audio goes that is _much_ more sophisticated and precise than, for
example, our "mixer" interface.

I really think it is tremendously wrong to produce a telephony interface
unlike every other extant one, one bent to look like a simple audio
driver when in fact one would really like to _avoid_ having to treat the
audio data at all.

 Thor Lancelot Simon	                            
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud