From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261877AbTL1SZv (ORCPT ); Sun, 28 Dec 2003 13:25:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261889AbTL1SZu (ORCPT ); Sun, 28 Dec 2003 13:25:50 -0500 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:15115 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S261877AbTL1SZs (ORCPT ); Sun, 28 Dec 2003 13:25:48 -0500 Date: Sun, 28 Dec 2003 18:25:45 +0000 From: Russell King To: Linux Kernel List , Ingo Molnar Subject: Re: 2.6.0-test6: APM unable to suspend (the 2.6.0-test2 saga continues) Message-ID: <20031228182545.B20278@flint.arm.linux.org.uk> Mail-Followup-To: Linux Kernel List , Ingo Molnar References: <20031005171055.A21478@flint.arm.linux.org.uk> <20031228174622.A20278@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20031228174622.A20278@flint.arm.linux.org.uk>; from rmk+lkml@arm.linux.org.uk on Sun, Dec 28, 2003 at 05:46:22PM +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 28, 2003 at 05:46:22PM +0000, Russell King wrote: > Alan Cox has shed some light on this problem. He mentions that the > x86 GDT/LDT stuff changed around 2.5.30, which is the time when others > have also reported that their APM has stopped working. I've not > confirmed whether that is the case for me as well, but it seems to > be highly likely. > > I also asked Alan if there's the possibility of backing this out or > making it configurable, but the answer seems to be a most definite > no. However, maybe Ingo can say otherwise? > > This effectively means that people with laptops which do not work > with 2.6 APM nor ACPI can expect their machines to be stuck with 2.4 > for the future, unless someone with the necessary knowledge sees this > problem as important enough to solve. A quick follow-up from a discussion I've just had with Andi Kleen... Note that I know nothing about the x86 internals of LDT/GDT/APM stuff, so I'm clutching at straws here... Would it be possible to switch LDT/GDT to whatever the APM BIOS expects just before calling the APM BIOS to suspend/hibernate, and restore them to whatever Linux requires after the APM BIOS returns from resume? -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/ 2.6 Serial core