From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756501Ab2LLAp6 (ORCPT ); Tue, 11 Dec 2012 19:45:58 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39505 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754646Ab2LLAp4 (ORCPT ); Tue, 11 Dec 2012 19:45:56 -0500 Message-ID: <50C7D3AB.6060508@zytor.com> Date: Tue, 11 Dec 2012 16:45:31 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Ondrej Zary CC: Alan Cox , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Dmitry Torokhov Subject: Re: [PATCH v4] 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops References: <201212112218.06551.linux@rainbow-software.org> In-Reply-To: <201212112218.06551.linux@rainbow-software.org> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Looks good to me. Alan/Rafael/Dmitry, OK for me to commit this? -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; >