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 12:56:20 -0800 Message-ID: <50C79DF4.3020300@zytor.com> References: <201210261056.44225.zary@gsystems.sk> <201212112129.13248.linux@rainbow-software.org> <50C7995E.7060301@zytor.com> <201212112150.38410.linux@rainbow-software.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:35361 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753907Ab2LKU4d (ORCPT ); Tue, 11 Dec 2012 15:56:33 -0500 In-Reply-To: <201212112150.38410.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 12:50 PM, Ondrej Zary wrote: > On Tuesday 11 December 2012 21:36:46 H. Peter Anvin wrote: >> 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... > > Could you please create proper patch? You're the x86 expert (and I'm not). > > I've read that 0xd1 command with 0xdf data is often used to enable A20. But I > don't know when this must be done or what else needs to be done for the SMM > to not break. > You need to send an FF dummy command afterwards, that's all. -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.