Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261270AbVBJS6q (ORCPT ); Thu, 10 Feb 2005 13:58:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261322AbVBJS6p (ORCPT ); Thu, 10 Feb 2005 13:58:45 -0500 Received: from mail.tmr.com ([216.238.38.203]:2443 "EHLO gaimboi.tmr.com") by vger.kernel.org with ESMTP id S261290AbVBJS56 (ORCPT ); Thu, 10 Feb 2005 13:57:58 -0500 Message-ID: <420BB267.8060108@tmr.com> Date: Thu, 10 Feb 2005 14:13:43 -0500 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040616 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox CC: Pavel Machek , Jon Smirl , ncunningham@linuxmail.org, Carl-Daniel Hailfinger , ACPI List , Linux Kernel Mailing List Subject: Re: [RFC] Reliable video POSTing on resume (was: Re: [ACPI] Samsung P35, S3, black screen (radeon)) References: <20050205093550.GC1158@elf.ucw.cz> <1107695583.14847.167.camel@localhost.localdomain> In-Reply-To: <1107695583.14847.167.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1572 Lines: 37 Alan Cox wrote: > On Sad, 2005-02-05 at 09:35, Pavel Machek wrote: > >>Rumors say that notebooks no longer have video bios at C000h:0; rumors >>say that video BIOS on notebooks is simply integrated into main system >>BIOS. I personaly do not know if rumors are true, but PCs are ugly >>machines.... >> > > > A small number of laptop systems are known to pull this trick. There are > other problems too - the video bios boot may make other assumptions > about access to PCI space, configuration, interrupts, timers etc. > > Some systems (intel notably) appear to expect you to use the bios > save/restore video state not re-POST. Isn't that what it's there for? In any context other than save/restore I wouldn't think using the BIOS was a good approach. But this is a special case, and if there's a BIOS function which does the right thing, it would seem to be easier to assume that the BIOS works than that the driver can do every operation for a clean restart. The problem is that while POST leaves the video in a known state, it may not the known state you want, nor is it a given that you can get from there to where you were on suspend. PC hardware isn't always that dependable. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979 - 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/