From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH v3] Enable A20 using KBC for some MSI laptops to fix S3 resume Date: Tue, 11 Dec 2012 12:36:46 -0800 Message-ID: <50C7995E.7060301@zytor.com> References: <201210261056.44225.zary@gsystems.sk> <201212111959.15808.linux@rainbow-software.org> <50C78486.9070700@zytor.com> <201212112129.13248.linux@rainbow-software.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:34889 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753104Ab2LKUhL (ORCPT ); Tue, 11 Dec 2012 15:37:11 -0500 In-Reply-To: <201212112129.13248.linux@rainbow-software.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Ondrej Zary Cc: Alan Cox , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On 12/11/2012 12:29 PM, Ondrej Zary wrote: > > Something like this? (It works.) > Something like that. We need to make sure we send the proper sequence, though, or it might break some SMM firmware... > diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h > index d6cc77a..0807ac7 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 +961,13 @@ 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); > #endif /* CONFIG_X86 */ > > return retval; >