Subject: Re: wpi0: Full open source driver at openbsd
To: None <tech-kern@NetBSD.org>
From: David Young <dyoung@pobox.com>
List: tech-kern
Date: 10/08/2007 12:35:52
On Mon, Oct 08, 2007 at 08:55:36AM +0200, Joerg Sonnenberger wrote:
> On Sun, Oct 07, 2007 at 09:07:33PM -0500, David Young wrote:
> > You are mistaken when you put WiFi firmware in the same category as ROM
> > chips, microcode, and ASICs.
> 
> >From the QA many vendors put into the images -- yes. From the technical
> perspective -- no.
> 
> > Firmwares ordinarily add complexity to a microcontroller-based WiFi
> > that is way out of proportion to what is necessary to use the chip.
> > Bugs accompany that complexity, but documentation does not.
> 
> It depends. I can understand some of the reasons to put things in the
> firmware, the biggest being that it avoids the driver having to deal
> with environment specific issues that are very specific to individual
> versions of a device. Given all the interactions necessary for good
> radio operations, doing everything in software seems like a bad idea.

Joerg,

Do you think you can bring an example of a WiFi firmware with a stable ABI
and documentation, without long-lived and notorious bugs, that strikes
a balance of responsibilities between the host and the microcontroller
so that the firmware is not complicated by fulfilling roles that the
host could do equally well or better?  It seems to me that industry
has not produced such a quality WiFi firmware, and the odds are against
one appearing.

I believe the inherent flexibility of a microcontroller-based design,
as compared with an ASIC or microcode, coupled with the peculiarly low
quality and unnecessary complexity of WiFi firmwares, adds up to a worse
threat than that posed by, say, ASIC bugs.

Dave

-- 
David Young             OJC Technologies
dyoung@ojctech.com      Urbana, IL * (217) 278-3933 ext 24