Subject: Re: New iwlwifi 3945 uCode available
From: reinette chatre <reinette.chatre@linux.intel.com>
To: Marcel Holtmann <holtmann@linux.intel.com>
Cc: Tomas Winkler <tomasw@gmail.com>,
	"John W. Linville" <linville@tuxdriver.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
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	 <1ba2fa240810211453y40739183v84999364c89886ee@mail.gmail.com>
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Content-Type: text/plain
Date: Tue, 21 Oct 2008 15:28:08 -0700
Message-Id: <1224628088.10863.100.camel@rc-desk> (sfid-20081022_002809_657213_850F002E)
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

On Tue, 2008-10-21 at 15:13 -0700, Marcel Holtmann wrote:
> Hi Tomas,
> 
> > >> > > On Tue, 2008-10-21 at 11:27 -0700, reinette chatre wrote:
> > >> > >> Two new versions of 3945 uCode is now available for download from
> > >> > >> http://intellinuxwireless.org/?n=Downloads. Two versions are available
> > >> > >> as we have updated the API version of the uCode and included pending
> > >> > >> fixes in both API versions.
> > >> > >>
> > >> > >> Version 15.28.1.8 supports API v1 and can be used with most current 3945
> > >> > >> drivers. Version 15.28.2.8 (API v2) is required when you start using the
> > >> > >> latest 3945 driver from wireless-testing at the time it includes the
> > >> > >> patch "iwl3945 : Fix a-band association for passive channels".
> > >> > >
> > >> > > Can you make the driver work with the old ucode? We even do that for
> > >> > > drivers where we don't control the ucode like b43...
> > >> >
> > >> > What for?
> > >>
> > >> Well, so that installing a new kernel doesn't suddenly break your
> > >> network connection and ability to download the firmware, for instance.
> > >> If you want more arguments you can go read all the "b43 sucks" threads
> > >> about it.
> > >
> > > Johnannes has a point, that is a lot nicer to users...
> >
> > Maybe, but it will complicate the code beyond good taste to just
> > satisfy the single moment when kernel is upgraded. I don't mean in
> > general I mean in this particular case when API changes.
> > Anyhow a good distro shell deal with this in packaging dependencies
> > and normal person will keep old kernel around when compiling new one.
> > Both ucodes can be present on the file system at the same time  so I
> > hope the risk is low.
> 
> it is the same argument as for everything else. We should be able to run
> a new kernel with old userspace.

I do not believe our request is unreasonable. If a user runs a new
kernel the log will print a message that the firmware is incorrect ...
all the user needs to do is go to
http://intellinuxwireless.org/?n=Downloads and download the latest
firmware. This does not require any subtle changes that may affect other
aspects of the system ... just the firmware file that is only used by
the driver.

We are focused on upstream development. If there is a need to support
older ucode then we face a similar challenge as was solved through the
compat-wireless project for the driver self.

Reinette