From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCD07C4361B for ; Wed, 16 Dec 2020 15:59:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87E1223104 for ; Wed, 16 Dec 2020 15:59:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726654AbgLPP7F (ORCPT ); Wed, 16 Dec 2020 10:59:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:47194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725957AbgLPP7F (ORCPT ); Wed, 16 Dec 2020 10:59:05 -0500 Date: Wed, 16 Dec 2020 15:58:20 +0000 From: Catalin Marinas To: Lecopzer Chen Cc: mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, matthias.bgg@gmail.com, will@kernel.org, yj.chiang@mediatek.com Subject: Re: [PATCH] arm64: Kconfig: Add SYS_SUPPORTS_APM_EMULATION Message-ID: <20201216155820.GH2511@gaia> References: <20201125103637.GC70906@C02TD0UTHF1T.local> <20201125114130.507-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201125114130.507-1-lecopzer.chen@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 25, 2020 at 07:41:30PM +0800, Lecopzer Chen wrote: > >> In order to select CONFIG_APM_EMULATION, make SYS_SUPPORTS_APM_EMULATION > >> default is y if ACPI isn't configured. > > > >I'm a bit confused why this should be enabled for !ACPI. Which DT > >platforms need this, and how do they use it? Why should this only be > >enabled for kernels without ACPI support, and not for kernels that > >support both ACPI and DT? > > In our internal patch has no !ACPI here, > the reason I add here is that in kernel document[1] it mention: > > No, sorry, you cannot have both ACPI and APM enabled and running at once. > Thus, I try to limit the scope for who don't use the ACPI because I'm not sure > they could exist at the same time or not. > > But I think it should be fine without !ACPI if APM and APCI > config won't conflict with each other. > > So if it's better to remove !ACPI I'll send v2 for this. > > BTW, The platform is for our internal kernel drivers, they utilize APM interface, > /dev/apm_bios to do their works in arm64. Sorry, I don't think the APM interface makes sense on an arm64 kernel (and it's also used by an out of tree driver). -- Catalin