From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin O'Connor Subject: Re: [PATCH 0/4] acpi: fix up EJ0 in DSDT Date: Thu, 22 Sep 2011 00:35:13 -0400 Message-ID: <20110922043513.GA488@morn.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Amos Kong , seabios@seabios.org, Gleb Natapov , kvm@vger.kernel.org, jasowang@redhat.com, alex williamson , Marcelo Tosatti To: "Michael S. Tsirkin" Return-path: Received: from mail-vw0-f42.google.com ([209.85.212.42]:39432 "EHLO mail-vw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999Ab1IVEfT (ORCPT ); Thu, 22 Sep 2011 00:35:19 -0400 Received: by vwl1 with SMTP id 1so4086060vwl.1 for ; Wed, 21 Sep 2011 21:35:18 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Sep 21, 2011 at 03:44:13PM +0300, Michael S. Tsirkin wrote: > The reason is that our acpi tables declare both _RMV with value 0, > and _EJ0 method for these slots. What happens in this case > is undocumented by ACPI spec, so linux ignores _RMV, > and windows seems to ignore _EJ0. Could the DSDT just not define _EJ0 for device 1 & 2 instead of dynamically patching them? (Would there ever be a case where we wouldn't know at compile time which devices need _EJ0?) > The correct way to suppress hotplug is not to have _EJ0, > so this is what this patch does: it probes PIIX and > modifies DSDT to match. The code to generate basic SSDT code isn't that difficult (see build_ssdt and src/ssdt-proc.dsl). Is there a compelling reason to patch the DSDT versus just generating the necessary blocks in an SSDT? -Kevin