From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760124AbbA1V3X (ORCPT ); Wed, 28 Jan 2015 16:29:23 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:45498 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933423AbbA1Urx (ORCPT ); Wed, 28 Jan 2015 15:47:53 -0500 Message-ID: <54C92804.5090806@codeaurora.org> Date: Wed, 28 Jan 2015 12:18:44 -0600 From: Timur Tabi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Catalin Marinas CC: "hanjun.guo@linaro.org" , "Rafael J. Wysocki" , Olof Johansson , Arnd Bergmann , Mark Rutland , "grant.likely@linaro.org" , Will Deacon , "linaro-acpi@lists.linaro.org" , "wangyijing@huawei.com" , Rob Herring , "linux-acpi@vger.kernel.org" , "phoenix.liyi@huawei.com" , Robert Richter , Jason Cooper , Marc Zyngier , "jcm@redhat.com" , Mark Brown , Bjorn Helgaas , "linux-arm-kernel@lists.infradead.org" , Randy Dunlap , lkml Subject: Re: [Linaro-acpi] [PATCH v7 04/17] ARM64 / ACPI: Introduce early_param for "acpi" and pass acpi=force to enable ACPI References: <1421247905-3749-1-git-send-email-hanjun.guo@linaro.org> <1421247905-3749-5-git-send-email-hanjun.guo@linaro.org> <20150128181453.GG31752@e104818-lin.cambridge.arm.com> In-Reply-To: <20150128181453.GG31752@e104818-lin.cambridge.arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/28/2015 12:14 PM, Catalin Marinas wrote: >> >So it looks like there's a whole conversation about this already in >> >this thread that I didn't notice. However, reading through all of it, >> >I still don't understand sure why the presence of ACPI tables is >> >insufficient to enable ACPI. > Because ACPI on arm64 is still experimental, no matter how many people > claim that it is production ready in their private setups. Fair enough. Does this mean that passing "acpi=force" on the kernel command line is a requirement for ARM64 servers? >> >In what situation would we want to ignore ACPI tables that are >> >present? > When DT tables are also present (and for the first platforms, that's > highly recommended, though not easily enforceable at the kernel level). My understanding is that the EFI stub creates a device tree (and it contains some important information), so I don't understand how we can ever have an ACPI-only platform on ARM64 servers. -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.