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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2F3CFC433DF for ; Tue, 4 Aug 2020 15:08:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13AEE2086A for ; Tue, 4 Aug 2020 15:08:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729454AbgHDPIv (ORCPT ); Tue, 4 Aug 2020 11:08:51 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:52741 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728467AbgHDPIq (ORCPT ); Tue, 4 Aug 2020 11:08:46 -0400 X-Originating-IP: 86.202.118.225 Received: from localhost (lfbn-lyo-1-23-225.w86-202.abo.wanadoo.fr [86.202.118.225]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id D16071C0006; Tue, 4 Aug 2020 15:08:41 +0000 (UTC) Date: Tue, 4 Aug 2020 17:08:41 +0200 From: Alexandre Belloni To: Claudiu.Beznea@microchip.com Cc: Nicolas.Ferre@microchip.com, Ludovic.Desroches@microchip.com, wenyou.yang@atmel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/3] ARM: at91: pm: add per soc validation of pm modes Message-ID: <20200804150841.GA10725@piout.net> References: <1596539258-20719-1-git-send-email-claudiu.beznea@microchip.com> <1596539258-20719-3-git-send-email-claudiu.beznea@microchip.com> <20200804114223.GC7836@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/08/2020 15:00:38+0000, Claudiu.Beznea@microchip.com wrote: > > > On 04.08.2020 14:42, Alexandre Belloni wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > > Hello, > > > > On 04/08/2020 14:07:37+0300, Claudiu Beznea wrote: > >> void __init at91rm9200_pm_init(void) > >> { > >> + static const int modes[] __initconst = { > > > > You don't need that to be static as it is now local to the function. > > > >> + AT91_PM_STANDBY, AT91_PM_ULP0 > >> + }; > >> + > >> if (!IS_ENABLED(CONFIG_SOC_AT91RM9200)) > >> return; > >> > >> + at91_pm_modes_validate(modes, ARRAY_SIZE(modes)); > > > > For rm9200 and at91sam9, I would not allow changing the pm_modes and > > simply enforce standby_mode = AT91_PM_STANDBY and suspend_mode = > > AT91_PM_ULP0.I don't think you have any user that ever changed that > > behaviour also that avoids increasing the boot time for those slow SoCs. > > OK, but bootargs is parsed at a moment when there is no information about > the machine that is running the code. And enforcing this in *_pm_init() > functions for rm9200 and at91sam9 may change suspend and standby mode that > user selected. If there is no user up to this moment there is still the > possibility of being one in the future. > So let's prevent users from doing that. Unused arguments are silently ignored which is exactly what we want to do. You won't make me believe there is actually a use case for swapping the standby and suspend meanings. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com