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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 1C250C3F68F for ; Tue, 7 Jan 2020 13:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E253D2081E for ; Tue, 7 Jan 2020 13:57:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=rere.qmqm.pl header.i=@rere.qmqm.pl header.b="kbjY1UiP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728138AbgAGN5v (ORCPT ); Tue, 7 Jan 2020 08:57:51 -0500 Received: from rere.qmqm.pl ([91.227.64.183]:43075 "EHLO rere.qmqm.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727658AbgAGN5u (ORCPT ); Tue, 7 Jan 2020 08:57:50 -0500 Received: from remote.user (localhost [127.0.0.1]) by rere.qmqm.pl (Postfix) with ESMTPSA id 47sYqJ14XNz81; Tue, 7 Jan 2020 14:57:48 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rere.qmqm.pl; s=1; t=1578405468; bh=BoDbS0Y77Y46eqRee+OSdUUGKre0sFOIVfgYgRLHBGg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kbjY1UiP9HTz1ohnf71liNTB6gld9zHzWo+R2tRC+y3TUgHFE5JlPdOWq0f+Ecvwn vweWiW6WGv9vE0Zcc66WE5RdzREbR8HaDDhF+ZiZn3mOZc7A1ZtNiG+eiWny3i1FTK 5jGP2j/y9Xbbj1IMZSsl3aOcn+GkDmDUEf3vnlJvHCDCt9S9/u/O1jiDjERnghiwwS VdWMqR1mhMlO6ZVZAs4MCH+3Yh3rAFpYT9Y5/S8hLmCwg6PYlZV8Guw29VZA3wEGcd TpTbC+PYDRhWbuR1V3PJBW/uaLw44qyrrEhwc6jGkJHzmakMgxrLsb/TsKo7A767uu EVcH17+qvDrNQ== X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.101.4 at mail Date: Tue, 7 Jan 2020 14:57:43 +0100 From: =?iso-8859-2?Q?Micha=B3_Miros=B3aw?= To: Viresh Kumar Cc: Nishanth Menon , Stephen Boyd , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] opp: quiet down WARN when no valid OPPs remain Message-ID: <20200107135743.GA20159@qmqm.qmqm.pl> References: <5c2d6548aef35c690535fd8c985b980316745e91.1578077228.git.mirq-linux@rere.qmqm.pl> <20200107064128.gkeq2ejtvx4bmyhj@vireshk-i7> <20200107095834.GB3515@qmqm.qmqm.pl> <20200107113055.d4ebweisve73yf3m@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200107113055.d4ebweisve73yf3m@vireshk-i7> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 07, 2020 at 05:00:55PM +0530, Viresh Kumar wrote: > On 07-01-20, 10:58, Michał Mirosław wrote: > > On Tue, Jan 07, 2020 at 12:11:29PM +0530, Viresh Kumar wrote: > > > On 03-01-20, 20:36, Michał Mirosław wrote: > > > > Per CPU screenful of backtraces is not really that useful. Replace > > > > WARN with a diagnostic discriminating common causes of empty OPP table. > > > But why should a platform have an OPP table in DT where none of them works for > > > it ? I added the warn intentionally here just for that case. > > Hmm. I guess we can make it WARN_ON_ONCE instead of removing it > I am not sure this will get triggered more than once normally anyway, isn't it ? It is triggered once per core. > > , but I > > don't think the backtrace is ever useful in this case. > Hmm, I am less concerned about backtraces than highlighting problem in a serious > way. The simple print messages are missed many times by people and probably > that's why I used a WARN instead. > > > Empty table can > > be because eg. you run old DT on newer hardware version. > > Hmm, but then a big warning isn't that bad as we need to highlight the issue to > everyone as cpufreq won't be working. isn't it ? A user normally can't do much about it. Rather this is a developer targeted message. Maybe a rewording of the messages be better? Something to also include consequences of the error? Best Regards, Michał Mirosław