From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH v4] 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops Date: Wed, 12 Dec 2012 10:48:31 -0800 Message-ID: <20121212184831.GA10521@core.coreip.homeip.net> References: <201212112218.06551.linux@rainbow-software.org> <50C7D3AB.6060508@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:48511 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754461Ab2LLSsh (ORCPT ); Wed, 12 Dec 2012 13:48:37 -0500 Content-Disposition: inline In-Reply-To: <50C7D3AB.6060508@zytor.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "H. Peter Anvin" Cc: Ondrej Zary , Alan Cox , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, Dec 11, 2012 at 04:45:31PM -0800, H. Peter Anvin wrote: > Looks good to me. Alan/Rafael/Dmitry, OK for me to commit this? Sure. I hope it won't affect other boxes, otherwise more DMI tables will be needed. Thanks. > > -hpa > > On 12/11/2012 01:18 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 in i8042_platform_init for x86. > > > > Fixes https://bugzilla.kernel.org/show_bug.cgi?id=12878 > > > > Signed-off-by: Ondrej Zary > > --- > > drivers/input/serio/i8042-x86ia64io.h | 9 +++++++++ > > 1 files changed, 9 insertions(+), 0 deletions(-) > > > > 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; > > > -- Dmitry