From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932102Ab2L1Tph (ORCPT ); Fri, 28 Dec 2012 14:45:37 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55220 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754688Ab2L1TSK (ORCPT ); Fri, 28 Dec 2012 14:18:10 -0500 Message-Id: <20121228190356.249264887@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:05:34 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ondrej Zary , Dmitry Torokhov , "Rafael J. Wysocki" , "H. Peter Anvin" Subject: [ 124/173] x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ondrej Zary commit ad68652412276f68ad4fe3e1ecf5ee6880876783 upstream. 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 in i8042_platform_init for x86. Fixes https://bugzilla.kernel.org/show_bug.cgi?id=12878 Signed-off-by: Ondrej Zary Cc: Dmitry Torokhov Cc: Alan Cox Cc: Rafael J. Wysocki Link: http://lkml.kernel.org/r/201212112218.06551.linux@rainbow-software.org Signed-off-by: H. Peter Anvin Signed-off-by: Ben Hutchings --- drivers/input/serio/i8042-x86ia64io.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h index d6cc77a..5f306f7 100644 --- a/drivers/input/serio/i8042-x86ia64io.h +++ b/drivers/input/serio/i8042-x86ia64io.h @@ -921,6 +921,7 @@ static int __init i8042_platform_init(void) int retval; #ifdef CONFIG_X86 + u8 a20_on = 0xdf; /* Just return if pre-detection shows no i8042 controller exist */ if (!x86_platform.i8042_detect()) return -ENODEV; @@ -960,6 +961,14 @@ static int __init i8042_platform_init(void) if (dmi_check_system(i8042_dmi_dritek_table)) i8042_dritek = true; + + /* + * A20 was already enabled during early kernel init. But some buggy + * BIOSes (in MSI Laptops) require A20 to be enabled using 8042 to + * resume from S3. So we do it here and hope that nothing breaks. + */ + i8042_command(&a20_on, 0x10d1); + i8042_command(NULL, 0x00ff); /* Null command for SMM firmware */ #endif /* CONFIG_X86 */ return retval;