From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Subject: Re: [PATCH v3] Enable A20 using KBC for some MSI laptops to fix S3 resume Date: Tue, 11 Dec 2012 19:59:15 +0100 Message-ID: <201212111959.15808.linux@rainbow-software.org> References: <201210261056.44225.zary@gsystems.sk> <201211052135.20009.linux@rainbow-software.org> <50C6537A.9090303@zytor.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50C6537A.9090303@zytor.com> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Alan Cox , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-acpi@vger.kernel.org On Monday 10 December 2012 22:26:18 H. Peter Anvin wrote: > On 11/05/2012 12:35 PM, Ondrej Zary wrote: > > On Friday 26 October 2012 10:56:44 Ondrej Zary wrote: > >> Some MSI laptop BIOSes are broken - INT 15h code uses port 92h to enable > >> A20 line but resume code assumes that KBC was used. > >> The laptop will not resume from S3 otherwise but powers off after a > >> while and then powers on again stuck with a blank screen. > >> > >> Fix it by enabling A20 using KBC. Affected laptop list and DMI data are > >> from bug reports at Ubuntu Launchpad. > >> > >> Also add kernel parameter to easily activate this quirk on any system. > >> > >> Only compile tested. The original patch was tested with EX600 and PR200. > >> > >> Fixes https://bugzilla.kernel.org/show_bug.cgi?id=12878 > > > > The bug was marked as RESOLVED CODE_FIX but I wonder what happened to > > this patch. Was it applied? Or is someone working on a better way to fix > > this problem? > > Sorry, I managed to forget about this. > > Is there any way you could test this patch by any chance? I've just tested the patch and it does not work (no change in behavior). > I would be a lot happier if this works as a general solution rather than > relying on a quirk... As I said before, the BIOS probably breaks on resume before any Linux code is executed. So any fix must be done before suspending. I hate quirks too. A general solution would be to always enable A20 using KBC (if KBC is present) but that's probably not acceptable. -- Ondrej Zary