Need help to write a new driver for a new wireless device (not yet in the market).

[Darryl Smith]

Hello All,

This post is a bit longer than I had wanted. Still, it says a lot too... 

I truly wish I could help Sriharsha on this issue. I just do not have the
time, or the knowledge of the internals of the Linux wireless driver. It
would be fun for me to learn, but I have not got the time at the moment. It
has been 10 years since I worked on a Wireless driver for Linux. And in that
time things have changes a lot (Yes my friend, there was Wireless back in
1997! I did write a paper on this
(http://www.radio-active.net.au/webran/articles/papers/dcc1997.doc; and I
have been using Linux since Minix)

So, why should we help him? Well, by answering the questions we all learn.
Phil Karn, KA9Q, (Karn's Algorithm for exponential packet backoff) is famous
for saying that the best way to learn something is to have to explain it to
someone else. I totally agree with that. The questions that Sriharsha is
asking are reasonable to understand the low level wireless interfaces. And
that improves the knowledge within the community. 

And from I have already learned from the Questions. And the answers would be
very useful. 

As for the whole Open Vs. Closed source issue for wireless drivers. I have
heard a heap on the issue from people like Bob McGwyer, Bruce Perens and
Bdale Garbe, and discussed the issue with some of these people. If you have
no idea who they are then you might want to do a bit of research. Each are
involved in some way with the Software Defined Radio and Open Source world.
I am also on the board of a Wireless Non-Profit R&D Organisation in the USA
- an organization whose annual conference proceedings was used as the prior
art to stop the patenting of Java, and who co-developed the protocol that
the name SSID with WiFi was borrowed from (AX-25 is the protocol, and TAPR
is the Organisation). Then there is the work of Matt Ettus and Gerard
Youngblood... 

The area of Software Defined Radios needs a re-thinking of the entire Open
Source world. In many cases there are legal reasons for full source code not
being released. I am not talking about NDA's here. I am talking about
serious restrictions where a company might be liable to a fine in excess of
$250,000 *each time* they permit their device to be used with modified
source code.

There is a vast legislative difference between a video card and a wireless
card. There is no constitutional coverage for video cards in the Australian
constitution, but there is for Wireless cards Section 51(V). There is
specific legislation applying to wireless cards, as opposed to video cards.
This would include the "Radiocommunications Act 1992", and maybe the
"Telecommunications Act 1997"

In Australia, what people believe is unlicensed is actually covered under a
class license. The importer needs to certify that they meet certain
technical requirements with the device. If the device is modified in any way
the class license no longer applies, and the device is operating illegally.
This could include operating with a different antenna, power amplifier, or
modified software. You see, when you change the firmware in these devices,
the regulatory filings no longer apply. 

And I am sure that many people will tell you that these days the drivers
actually upload firmware to devices. Regardless, some of the settings or
combination of the settings will cause situations where the device can
operate outside legal limits. And a manufacturer that allows this can be in
a heap of trouble. 

Many people take the "don't ask, don't tell" attitude to wireless. This is
wrong. Things are messy. Governments are trying to restrict high speed DAC
and ADCs for these type of reasons. Thankfully we have some people fighting
that.

What I am saying is that there is a case for closed source wireless drivers.
There is also a case for open source drivers. But to say that a person
should not be helped because the drivers will be closed source. Well, that
is short sighted. After all, how are you then going to reverse engineer the
driver to do cool stuff :-)

Darryl Smith VK2TDS
http://www.radio-active.net.au


-----Original Message-----
From: wireless-bounces+darryl=radio-active.net.au at lists.samba.org
[mailto:wireless-bounces+darryl=radio-active.net.au at lists.samba.org] On
Behalf Of Daniel Rose
Sent: Wednesday, 3 October 2007 7:43 AM
To: wireless at lists.samba.org
Subject: Re: Need help to write a new driver for a new wireless device (not
yet in the market).

Sriharsha Vedurmudi wrote:
> Hello Benjamin,
>  As much as I want to share the spec, but I am under strict legal
> agreements not to share it with anyone (not even outside our team).
> Another case of corporate dictatorship, but I am helpless. Sorry about
> it.


Much as I usually don't like to chime in with a negative comment, I will
anyway.  It's OK in this case because I don't know enough to be able to help
anyway, so you're not missing out on anything.

If a company wishes to develop something, and not share the details with the
community, why should anyone in the community help the company?

If this hardware takes off, then there will be more hardware around that
requires "tainting" the kernel, especially at a time when we are having wins
moving the other way (ATI, for example).

If it doesn't, then we're all wasting our time; even the software that might
potentially be useful to someone else will be discarded.


>  But the good news is that, this particular chip might not hit the
> markets, atleast not in volumes in the coming future.
> 

How is that good news?  Why make it if you won't sell it?