From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 10.25.159.19 with SMTP id i19csp1221689lfe; Wed, 13 Jan 2016 08:26:22 -0800 (PST) X-Received: by 10.55.27.164 with SMTP id m36mr36553608qkh.84.1452702382077; Wed, 13 Jan 2016 08:26:22 -0800 (PST) Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id j61si2011306qgj.96.2016.01.13.08.26.21 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 13 Jan 2016 08:26:22 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Received: from localhost ([::1]:38047 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aJOFZ-0003u1-L9 for alex.bennee@linaro.org; Wed, 13 Jan 2016 11:26:21 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55371) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aJOFU-0003sU-5y for qemu-arm@nongnu.org; Wed, 13 Jan 2016 11:26:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aJOFT-0006ss-FL for qemu-arm@nongnu.org; Wed, 13 Jan 2016 11:26:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44180) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aJOFT-0006sc-9p; Wed, 13 Jan 2016 11:26:15 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id D0F94C09FA9B; Wed, 13 Jan 2016 16:26:14 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com ([10.3.113.3]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u0DGQCbg020142; Wed, 13 Jan 2016 11:26:13 -0500 To: Andrew Jones , Shannon Zhao References: <1452696857-4091-1-git-send-email-shannon.zhao@linaro.org> <20160113161641.GC10709@hawk.localdomain> From: Laszlo Ersek Message-ID: <56967AA4.40300@redhat.com> Date: Wed, 13 Jan 2016 17:26:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160113161641.GC10709@hawk.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: peter.maydell@linaro.org, ard.biesheuvel@linaro.org, edk2-devel@ml01.01.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, zhaoshenglong@huawei.com Subject: Re: [Qemu-arm] [Qemu-devel] [PATCH v2] ARM: Virt: Don't generate RTC ACPI device when using UEFI X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: lyYJK3Zucwd9 On 01/13/16 17:16, Andrew Jones wrote: > On Wed, Jan 13, 2016 at 10:54:17PM +0800, Shannon Zhao wrote: >> When booting the VM with UEFI, UEFI takes ownership of the RTC hardware. >> While UEFI can use libfdt to disable the RTC device node in the DTB that >> it passes to the OS, it cannot modify AML. Therefore, we won't generate >> the RTC ACPI device at all when using UEFI. > > I think a condensed comment similar to this commit message would be nice > in build_dsdt, or somewhere. We have a policy for mach-virt of generating > ACPI for everything we generate DT. It'd be good if we documented all the > divergences in order to avoid confusion. [...] Good idea! Thanks Laszlo