Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753842Ab3HBWLK (ORCPT ); Fri, 2 Aug 2013 18:11:10 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:52709 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752800Ab3HBWLH (ORCPT ); Fri, 2 Aug 2013 18:11:07 -0400 From: "Rafael J. Wysocki" To: Felipe Contreras Cc: Linus Torvalds , ACPI Devel Maling List , LKML , Linux PM list Subject: Re: [GIT PULL] ACPI and power management fixes for v3.11-rc4 Date: Sat, 03 Aug 2013 00:21:19 +0200 Message-ID: <6100577.WGRZRabKGy@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: References: <2052880.bHfzt6NKt5@vostro.rjw.lan> <1820071.Lqgn6ZcLbB@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3223 Lines: 70 On Friday, August 02, 2013 04:31:37 PM Felipe Contreras wrote: > On Fri, Aug 2, 2013 at 4:21 PM, Rafael J. Wysocki wrote: > > On Friday, August 02, 2013 02:12:49 PM Felipe Contreras wrote: > > >> You forgot this patch: > >> > >> https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=3706231332d57072e0e2c0e59975443f3f18e673 > >> > >> Or do you think it's fine to boot these machines into a black screen? > > > > Seriously, what's wrong with you?! > > > > I didn't forget about it, I just didn't include it into this particular > > pull request. > > > > And I'm not even sure I will push it for 3.11, because I prefer to revert > > efaa14c for 3.11 if that's necessary to make your broken box work as before. > > The issue happens in more than just "my broken box", and yes, > reverting that patch would help (in more than just my box), in the > sense that at least Linux won't boot into a black screen. > > But the backlight control still wouldn't work, as it hasn't worked > since v3.7, possibly in many ASUS laptops, for that you need more than > just reverting efaa14c. Yes, last time it worked in 3.6 and in particular it doesn't work in 3.10. My current goal is bring things back to the 3.10 state first, possibly without introducing any new problems, because we're kind of late in the cycle. That's better done by reverting stuff known to have introduced problems in the first place and not by doing things that may introduce more of them. And your blacklisting patch has potential to introduce problems. Your goal is to bring backlight control to the 3.6 state on that particular machine, but the blacklist is done at the *system* level and very well may affect more things than just backlight. You may not see any problems resulting from it and you may not care even if there are some, but other users of it may use different user space, for example, and may see problems that you're not seeing. That's why I'd very much prefer to do the revert at this point. > > Well, perhaps I just won't push it at all so that you actually can go and > > complain to Linus about that ... > > That is very responsible from you. Screw the users, right? No, that's not my goal, sorry for disappointing you. The problem is that I'm not really convinced about the validity of the blacklisting approach to begin with. As I said, the blacklisting is done on the system level and the goal is to work around backlight control problems. That sounds like a sledgehammer approach to me, which I don't really like. If the blacklisting was more targeted, done at the video driver level etc., I wouldn't really have any concerns about it, but that's not the case. And since people evidently could live for over 6 months with the backlight control problems, maybe they'll survive some more time still and allow us to find a better approach? Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/