From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH] : ACPI : Use RSDT instead of XSDT by adding boot option of "acpi=rsdt" Date: Fri, 9 Jan 2009 12:34:16 +0000 Message-ID: <20090109123416.GA31003@srcf.ucam.org> References: <20081031184233.8588.42241.stgit@thinkpad> <200901091154.43606.trenn@suse.de> <200901091316.16334.trenn@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:52012 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752801AbZAIMeX (ORCPT ); Fri, 9 Jan 2009 07:34:23 -0500 Content-Disposition: inline In-Reply-To: <200901091316.16334.trenn@suse.de> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Thomas Renninger Cc: Len Brown , Zhao Yakui , "Linux-acpi@vger.kernel.org" , me@markdoughty.co.uk, ibm-acpi-devel@lists.sourceforge.net On Fri, Jan 09, 2009 at 01:16:15PM +0100, Thomas Renninger wrote: > IMO this cannot generally be done, because chances are high that machines > which do not support Windows likely will break. > Chances are high that a machine which does not support Windows uses 64 bit > addresses and leaves the 32 bit ones uninitialized, a spec valid configuration > which will then break. Bear in mind that the values in the 32-bit entries are *io port* addresses, not physical memory addresses. There's only 16 bits of io ports, so the probability of the 64-bit values being programmed correctly and the 32-bit ones containing a valid but not-working set is tiny. If you know of any machines that behave this way, I'd be impressed - and it'll be far easier to dmi whitelist them than the other way around. -- Matthew Garrett | mjg59@srcf.ucam.org