Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:60833 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834Ab1JJTbJ convert rfc822-to-8bit (ORCPT ); Mon, 10 Oct 2011 15:31:09 -0400 MIME-Version: 1.0 In-Reply-To: References: <1317721043.11231.2.camel@jmachine> From: "Luis R. Rodriguez" Date: Mon, 10 Oct 2011 12:30:45 -0700 Message-ID: (sfid-20111010_213127_294560_99FB3C2A) Subject: Re: [alsa-devel] Using spdiff for backporting To: Takashi Iwai Cc: Jesper Andersen , linux-wireless , alsa-devel@alsa-project.org, julia@diku.dk, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Oct 10, 2011 at 5:41 AM, Takashi Iwai wrote: > At Fri, 7 Oct 2011 10:41:06 -0700, > Luis R. Rodriguez wrote: >> >> > Also, in the slides from the plumbers-conf. I think I saw it mentioned >> > that there's also an alsa-compat git-tree somewhere. Maybe that is a >> > more compelling usecase? I was unable to find it though so I'd >> > appreciate a link. >> >> It was on kernel.org, but if it got rm -rf'd then its gone as I do not >> have a local copy. > > Oh, I didn't know of such a tree.  So you created alsa driver build > system with your spdiff?  That's interesting. Nope, this was pre-spdiff days. It was just a proof of concept I wanted to make just to see how long it would take me to do it and how clean it was. It was pretty trivial. I'm now working with Jesper on seeing how best we can use spdiff for a unified backport of the kernel. >> The compat-alsa stuff though was determined to be >> superflous with the ALSA's team's own backport work which is currently >> independent. > > Yes, the external alsa-driver build tree has existed since 10 years > ago :)  It was even possible to build with 2.2/2.4 kernels until > recently. > > The current tree is found in github, >        git://github.com/tiwai/alsa-driver-build.git That's pretty darn impressive. >> My hope though is to unify these through the compat.git / >> compat-kernel (currently just called compat-wireless) effort. > > The common framework would be really nice to have. Agreed! > V4L also have own build system, and possible other subsystem trees too. Heh, yeah for Video at least Ubuntu guys just backported a newer DRM into their distro kernel. I feel as if a generic backport would make more sense. I have already split out all generic kernel backport stuff into its own module, compat.git, and anything else that cannot be backported within an independent module we'e kept on compat-wireless. compat-wireless at this point should really be called compat-net but I've been lazy to rename it. At plumbers I put together slides for metrics of what goes into compat or compat-wireles, how many lines of code we pull and how much code consists of backport work. The conclusion was with compat backporting a new subsystem becomes proportionally easier. Then the legwork to keep compat-wireless up to date can benefit from spdiff as the spatches can eseentially generate new patches to help backport new drivers after just two drivers get backported for a condition which compat cannot address. The slides are at: http://bombadil.infradead.org/~mcgrof/presentations/backport/kernel-backport-for-good.pdf Luis