Subject: Re: [PATCH 00/20] staging: brcm80211: 7th reaction for mainline
 patch #2
From: Johannes Berg <johannes@sipsolutions.net>
To: Greg KH <greg@kroah.com>
Cc: Franky Lin <frankyl@broadcom.com>, gregkh@suse.de,
	devel@linuxdriverproject.org, linux-wireless@vger.kernel.org
In-Reply-To: <20110920130338.GA9885@kroah.com> (sfid-20110920_150440_808230_86E73445)
References: <1316467568-27683-1-git-send-email-frankyl@broadcom.com>
	 <20110920130338.GA9885@kroah.com> (sfid-20110920_150440_808230_86E73445)
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Date: Tue, 20 Sep 2011 15:21:14 +0200
Message-ID: <1316524874.3953.41.camel@jlt3.sipsolutions.net> (sfid-20110920_152126_182521_873B6871)
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

On Tue, 2011-09-20 at 06:03 -0700, Greg KH wrote:

> And while code is great and nice, I still haven't seen any real answers
> to all of the questions that were asked of the Broadcom driver team
> during that review by the linux-wireless developers about how things
> will be handled properly due to the overlap in functionality with the
> existing "real" driver in the tree.

Let's qualify this to "some developers".

One thing I'd like to point out is that the Broadcom's firmware API has
always undergone changes over time. I'm actually surprised that b43
works as well as it does (which, tbh, isn't very well at all, at least
for me with some 11n PHY). I also don't think that Broadcom are going to
maintain compatibility and/or maintain new firmware features for old
devices, that just doesn't make any sense.

As a consequence, I don't think there's any sense in saying b43 should
be the driver that Broadcom must support upstream. Even we, back then,
split b43 into b43 and b43legacy when it wasn't really possible any more
to test and maintain a single driver for different devices. Rafal has
shown that it is possible today (to some extent) to do that for the
newer chips and the older 11g only chips that b43 still supports, but
I'm not convinced that with new features like P2P this will be true in
the future.

And this is just discussing the technical side -- the support side is an
entirely different question.

Now, don't get me wrong -- I don't think the duplication is a good
thing. A lot of the PHY code could be shared. However, I think it will
probably not be possible for much longer to share the higher level MAC
code that programs the SHM etc.

So I don't claim to know what the solution is, but I think simply
rejecting the Broadcom effort like most people seem to imply is a good
solution at all. It will leave all of us in a bad spot by creating a
driver that has to support too many different devices.

johannes