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=-2.5 required=3.0 tests=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 9AF81C433DF for ; Fri, 26 Jun 2020 14:34:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76372207D8 for ; Fri, 26 Jun 2020 14:34:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726209AbgFZOeC (ORCPT ); Fri, 26 Jun 2020 10:34:02 -0400 Received: from foss.arm.com ([217.140.110.172]:55536 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbgFZOeB (ORCPT ); Fri, 26 Jun 2020 10:34:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 40B201FB; Fri, 26 Jun 2020 07:34:01 -0700 (PDT) Received: from bogus (unknown [10.37.12.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2AB3E3F6CF; Fri, 26 Jun 2020 07:33:57 -0700 (PDT) Date: Fri, 26 Jun 2020 15:33:55 +0100 From: Sudeep Holla To: Ulf Hansson Cc: Lorenzo Pieralisi , Saravana Kannan , linux-pm@vger.kernel.org, "Rafael J . Wysocki" , Daniel Lezcano , Lina Iyer , Vincent Guittot , Stephen Boyd , Bjorn Andersson , Benjamin Gaignard , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/5] cpuidle: psci: Fail cpuidle registration if set OSI mode failed Message-ID: <20200626143355.GC27140@bogus> References: <20200615152054.6819-1-ulf.hansson@linaro.org> <20200615152054.6819-2-ulf.hansson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200615152054.6819-2-ulf.hansson@linaro.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon, Jun 15, 2020 at 05:20:50PM +0200, Ulf Hansson wrote: > Currently we allow the cpuidle driver registration to succeed, even if we > failed to enable the OSI mode when the hierarchical DT layout is used. This > means running in a degraded mode, by using the available idle states per > CPU, while also preventing the domain idle states. > Is that not better than not registering itself ? I tend to disagree here. > Moving forward, this behaviour looks quite questionable to maintain, as > complexity seems to grow around it, especially when trying to add support > for deferred probe, for example. > I thought the sync_state in the driver must deal with that. > Therefore, let's make the cpuidle driver registration to fail in this > situation, thus relying on the default architectural cpuidle backend for > WFI to be used. > CPU level states work w/o the need of OSI, and better than WFI. That was the original aim. If that is not working, we must make it work instead of falling back on WFI IMO. -- Regards, Sudeep