From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59032) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cYwDt-00006V-UC for qemu-devel@nongnu.org; Wed, 01 Feb 2017 09:49:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cYwDp-0002zd-MN for qemu-devel@nongnu.org; Wed, 01 Feb 2017 09:49:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2983) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cYwDp-0002zI-Fw for qemu-devel@nongnu.org; Wed, 01 Feb 2017 09:49:21 -0500 Date: Wed, 1 Feb 2017 16:49:20 +0200 From: "Michael S. Tsirkin" Message-ID: <20170201164701-mutt-send-email-mst@kernel.org> References: <1484739954-86833-1-git-send-email-phil@philjordan.eu> <20170118175335-mutt-send-email-mst@kernel.org> <20170118181918.783cb7bd@nial.brq.redhat.com> <20170131165802-mutt-send-email-mst@kernel.org> <20170131201333-mutt-send-email-mst@kernel.org> <20170201123739.387de47b@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170201123739.387de47b@nial.brq.redhat.com> Subject: Re: [Qemu-devel] [PATCH RFC] acpi: add reset register to fadt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: Laszlo Ersek , Phil Dennis-Jordan , qemu-devel@nongnu.org, Paolo Bonzini , Richard Henderson , Eduardo Habkost On Wed, Feb 01, 2017 at 12:37:39PM +0100, Igor Mammedov wrote: > On Tue, 31 Jan 2017 20:17:02 +0200 > "Michael S. Tsirkin" wrote: > > > On Tue, Jan 31, 2017 at 05:28:57PM +0100, Laszlo Ersek wrote: > > > The ACPI 6.1 spec says, > > > > > > - DSDT: [...] If the X_DSDT field contains a non-zero value then this > > > field must be zero. > > > - X_DSDT: [...] If the DSDT field contains a non-zero value then this > > > field must be zero. > > > > But that's only 6.1. 6.0 and earlier did not say this. > > The errata they wanted to address was: > > 1393 In FADT: if X_DSDT field is non-zero, DSDT > > field should be ignored or deprecated > > > > I would class this as a spec bug. > > > > The same applies to X_PM1a_EVT_BLK and co, > for example 5.1 spec "This is a required > field." > > And looks like Windows implemented it as mandatory > to boot perhaps to be compatible with 5.1 and earlier > specs. > > It appears fw would be forced to fill fields depending > on table revision. Or just do what every hardware vendor does: 1. write according to spec 2. test a bunch of OSes, fix crashes -- MST