From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55420) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aJOFZ-0003tz-8G for qemu-devel@nongnu.org; Wed, 13 Jan 2016 11:26:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aJOFY-0006ua-9Y for qemu-devel@nongnu.org; Wed, 13 Jan 2016 11:26:21 -0500 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 MIME-Version: 1.0 In-Reply-To: <20160113161641.GC10709@hawk.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] ARM: Virt: Don't generate RTC ACPI device when using UEFI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Jones , Shannon Zhao 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 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