From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [RFT] x86 acpi: normalize segment descriptor register on resume Date: Sun, 13 Jul 2008 13:16:51 -0700 Message-ID: <487A62B3.8010207@zytor.com> References: <200807010148.02135.rjw@sisk.pl> <200807122253.32382.rjw@sisk.pl> <48793A0E.3050803@myrealbox.com> <200807130133.12324.rjw@sisk.pl> <20080713091524.GA29907@elte.hu> <20080713120253.GA27582@srcf.ucam.org> <487A2431.2050103@myrealbox.com> <487A4CB7.1080001@firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <487A4CB7.1080001@firstfloor.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Andi Kleen Cc: Andy Lutomirski , LKML , ACPI Devel Maling List , public-kernel-testers-u79uwXL29TY76Z2rM5mHXA@lo.gmane.org, Ingo Molnar , pm list List-Id: linux-acpi@vger.kernel.org Andi Kleen wrote: > > Hmm, but the change was not supposed to break the s3 bios. Something > fishy is going on. It sounds like the s3 bios relies on some earlier > segment register setup. > > If true this means the segment register reset would need to be moved > later after S3 bios ran. Saving/restoring is unfortunately not possible > because we cannot save/restore the hidden state loaded from the GDT earlier. > That really doesn't make sense, though. The VESA BIOS has to be entered in clean real mode; it's designed to be entered from reset, after all. There is definitely something fishy going on, but I don't think this particular aspect is it. What's *really* odd is that this was required with the old code but doesn't work at all with the new code. The former is understandable, the latter is not. -hpa