From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Subject: Re: [PATCH v2] Enable A20 using KBC for some MSI laptops to fix S3 resume Date: Thu, 25 Oct 2012 10:17:37 +0200 Message-ID: <201210251017.37750.linux@rainbow-software.org> References: <201210242316.22028.linux@rainbow-software.org> <50885BBB.9010904@zytor.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-1.atlantis.sk ([80.94.52.57]:54723 "EHLO mail.atlantis.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755469Ab2JYISJ (ORCPT ); Thu, 25 Oct 2012 04:18:09 -0400 In-Reply-To: <50885BBB.9010904@zytor.com> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "H. Peter Anvin" Cc: Alan Cox , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On Wednesday 24 October 2012, H. Peter Anvin wrote: > On 10/24/2012 02:16 PM, 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 > > Are we guaranteed that this executes *before* the keyboard driver > initializes? If not, this needs to use the i8042 interface in the input > subsystem or at least acquire i8042_lock. > > -hpa The code is called in: start_kernel()->setup_arch()->acpi_boot_table_init() I think that it's before any drivers are initialized. -- Ondrej Zary