Return-path: Received: from mail-ea0-f172.google.com ([209.85.215.172]:61055 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162074Ab3DERDR (ORCPT ); Fri, 5 Apr 2013 13:03:17 -0400 From: Christian Lamparter To: "Luis R. Rodriguez" Subject: Re: Version number policy! Date: Fri, 5 Apr 2013 19:03:09 +0200 Cc: Adrian Chadd , "ath9k_htc_fw" , "linux-wireless" , "linux-kernel@vger.kernel.org" , "linux-bluetooth" References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Message-Id: <201304051903.11215.chunkeey@googlemail.com> (sfid-20130405_190335_298958_DA67B80B) Sender: linux-wireless-owner@vger.kernel.org List-ID: On Friday 05 April 2013 10:19:00 Luis R. Rodriguez wrote: > On Thu, Apr 4, 2013 at 11:27 AM, Adrian Chadd wrote: > > 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. Based on my experience with carl9170, I can tell you that new stuff (new wmi commands, or advanced offload caps, features and bugfixes) should be advised via feature flags in bitmaps and not firmware versions. [Just make it long enough...] Otherwise you'll have to write endless checks like: if ((fw_minor == 1 && fw_patch > 30) || (fw_minor == 2 && fw_patch > 7) || (fw_minor == 3 && fw_patch > 3) || (fw_minor > 4)) feature_supported = true; everytime you backport features and bugfixes to older firmwares. Also, firmware dates are more important than you think. They allow some way of syncing the firmware->driver and your inbox. Regards, Christian