Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758150Ab0FFSFR (ORCPT ); Sun, 6 Jun 2010 14:05:17 -0400 Received: from www.tglx.de ([62.245.132.106]:41546 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756740Ab0FFSFH (ORCPT ); Sun, 6 Jun 2010 14:05:07 -0400 Date: Sun, 6 Jun 2010 20:04:17 +0200 (CEST) From: Thomas Gleixner To: James Bottomley cc: Alan Cox , Florian Mickler , Vitaly Wool , Brian Swetland , =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , Arjan van de Ven , tytso@mit.edu, Peter Zijlstra , "H. Peter Anvin" , LKML , Neil Brown , Linux PM , Ingo Molnar , Linux OMAP Mailing List , Linus Torvalds , Felipe Balbi Subject: Re: [linux-pm] suspend blockers & Android integration In-Reply-To: <1275844114.7227.552.camel@mulgrave.site> Message-ID: References: <1275834706.7227.545.camel@mulgrave.site> <1275844114.7227.552.camel@mulgrave.site> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3915 Lines: 89 James, On Sun, 6 Jun 2010, James Bottomley wrote: > On Sun, 2010-06-06 at 17:46 +0200, Thomas Gleixner wrote: > > On Sun, 6 Jun 2010, James Bottomley wrote: > > > > > > 3. We've lost sight of one of the original goals, which was to > > > bring the android tree close enough to the kernel so that the > > > android downstream driver and board producers don't have to > > > choose between the android kernel and vanilla kernel. > > > > There are two ways to do that w/o creating a dependcy on anything. > > > > 1) merge the drivers w/o the suspend_blockers. It's not rocket science > > to have a patch which brings them back for android. > > Well, we sort of tried this when Greg pulled some of them into the > staging tree. The problem is that without the annotations, the drivers > are still different, and patches won't apply, so, unsurprisingly, they > didn't get improved or even maintained. > > > 2) merge the drivers with empty stub implementations for annotation. > > android just has to patch in the real one. > > That's also possible. This time, we would have a cosmetically closer > tree ... however, what's in the kernel wouldn't be compilable for > android ... which is where all the downstream wants to test, so they'd > still be building for the android tree ... we just might have an easier > time of it picking up their fixes. The downstream users will be bound to the android tree anyway until the full set of drivers for a given platform is completely merged. So optimistically that would be 2.6.36, which gives us a couple of months to sort out the whole thing. Once a driver is merged mainline and the android tree switched over to use the mainline version, fixes can be sent both ways and that's not a real problem. > > While I'd prefer #1, I' not in the way of #2. > > I think 1 is unviable ... I'm not opposed to 2 but I'd like to try to > get the kernel really closer to android before we go for the cosmetic > only option. > > > Both ways can get the drivers into the kernel and it could/should have > > been done right from the beginning, but now we face a situation where > > drivers are held hostage. > > > > Then we can sit down more relaxed and fix the stuff in a way which > > makes both sides happy. If we manage to replace them, we can deprecate > > the stub implementation and remove it after a grace period. If we > > rename them it's not an issue either. We can rename them right away to > > a qos interface, but that does not really make a difference. > > > > What we really want to avoid is implementing an user space contract in > > a frenzy which binds us forever. > > Well, that's why the QoS proposal ... it already has a userspace API ... > we'd just be extending it for statistics, which looks like a wothwhile > goal independent of android anyway. Right, but there is no dependency for the driver merge on that. > > It's not the suspend_blockers which are the causing the nightmare, > > it's solely the drivers itself especially when there are different > > implementations in both trees. And frankly, the drivers in android are > > not in a shape which makes them flood in within 2 weeks. That's > > serious work to get them brushed up and polished. So that gives us > > quite a period of time to solve the suspend problem. > > Right, so the sooner we make it easier for the drivers to use the kernel > as their main repository, the better. Yep, the fastest way is to provide two stub inlines in pm.h and let the driver flood come in. I think all of us involved in that can do with a break, where we sit back, calm down and rethink w/o time pressure. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/