Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262851AbVDHQO6 (ORCPT ); Fri, 8 Apr 2005 12:14:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262863AbVDHQO6 (ORCPT ); Fri, 8 Apr 2005 12:14:58 -0400 Received: from [213.202.245.43] ([213.202.245.43]:29087 "EHLO buildd1.paldo.org") by vger.kernel.org with ESMTP id S262851AbVDHQOh (ORCPT ); Fri, 8 Apr 2005 12:14:37 -0400 Subject: [PATCH] Fix reloading GDT on ACPI S3 wakeup From: Juerg Billeter To: len.brown@intel.com Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: paldo Date: Fri, 08 Apr 2005 18:14:13 +0200 Message-Id: <1112976854.8880.15.camel@juerg-p4.bitron.ch> Mime-Version: 1.0 X-Mailer: Evolution 2.2.1.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1493 Lines: 43 Hi This patch - based on http://marc.theaimsgroup.com/?l=linux-kernel&m=110055503031009&w=2 - makes ACPI S3 wakeup work for me on a ThinkPad T40p laptop with a SMP kernel. Without it only UP kernels work. I've been using the patch for three months now without any issues. The ACPI resume code currently uses a real-mode 16-bit lgdt instruction to reload the GDT. This only restores the lower 24 bits of the GDT base address. In recent SMP kernels, the GDT seems to have moved out of the lower 16 megs, thereby causing the ACPI resume to fail -- an invalid GDT was being loaded. Regards, Juerg -- Signed-off-by: Juerg Billeter diff -uNr linux-2.6.10.orig/arch/i386/kernel/acpi/wakeup.S linux-2.6.10/arch/i386/kernel/acpi/wakeup.S --- linux-2.6.10.orig/arch/i386/kernel/acpi/wakeup.S 2004-12-24 22:34:26.000000000 +0100 +++ linux-2.6.10/arch/i386/kernel/acpi/wakeup.S 2005-01-08 23:34:38.551471486 +0100 @@ -74,8 +74,9 @@ movw %ax,%fs movw $0x0e00 + 'i', %fs:(0x12) - # need a gdt - lgdt real_save_gdt - wakeup_code + # need a gdt -- use lgdtl to force 32-bit operands, in case + # the GDT is located past 16 megabytes + lgdtl real_save_gdt - wakeup_code movl real_save_cr0 - wakeup_code, %eax movl %eax, %cr0 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/