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From: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Date: Fri, 5 Apr 2013 01:19:00 -0700
Message-ID: <CAB=NE6V3sApMSGWkKbaFaJC4+VpLxgYF-xyNRKxiA-YDCwhGkQ@mail.gmail.com>
Subject: Re: Version number policy!
To: Adrian Chadd <adrian@freebsd.org>
Cc: ath9k_htc_fw <ath9k_htc_fw@lists.infradead.org>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	linux-bluetooth <linux-bluetooth@vger.kernel.org>,
	Christian Lamparter <chunkeey@googlemail.com>
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On Thu, Apr 4, 2013 at 11:27 AM, Adrian Chadd <adrian@freebsd.org> wrote:
> Hi,
>
> Here's my first take on the version number policy:
>
> https://github.com/qca/open-ath9k-htc-firmware/wiki/VersionPolicy
>
> The summary:
>
> * major version number changes are for firmware API / behaviour
> changes that aren't backwards compatible;
> * minor version number changes are for firmware API / behaviour
> changes that are incremental and default to the old behaviour (eg, new
> optional commands);
> * the driver should check the minor version number before using any
> optional features with that version.
>
> What's TODO:
>
> * Add a new WMI command to get the build number, git string, etc.
> * add it as our first optional minor version command :-)

This is better than anything we had drafted before for 802.11 open
firmware design rules. Cc'ing a few lists for wider review given that
what we had written before for rules was for 802.11 and Bluetooth [0]
and it was very Linux specific. We are striving for open firmware here
for the community, for BSD / Linux. Christian would have dealt with
more of the support on open firmware design so far due to carl9170.fw
[1] so curious if he has any input.

As for 802.11 the rules we defined were pretty silly about firmware
file names but should be considered. Here's the key thing I think we
should keep from those old guidelines:

"In general if you are just providing bug fixes you do not need to
provide a new firmware filename for the module, using the old filename
is fine so long as the same API was kept."

The rest I think your specification details better what we should do
in terms of API changes for versioning.

[0] http://wireless.kernel.org/en/developers/Documentation/firmware-versioning
[1] http://wireless.kernel.org/en/users/Drivers/carl9170.fw

  Luis