From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752697AbcFPG5L (ORCPT ); Thu, 16 Jun 2016 02:57:11 -0400 Received: from mail-pf0-f174.google.com ([209.85.192.174]:33216 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751490AbcFPG5I (ORCPT ); Thu, 16 Jun 2016 02:57:08 -0400 Date: Thu, 16 Jun 2016 12:27:03 +0530 From: Viresh Kumar To: Alexandre Courbot Cc: Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, gnurou@gmail.com, linux-tegra@vger.kernel.org Subject: Re: [PATCH] PM / OPP: 'UNKNOWN' status of opp-table->shared Message-ID: <20160616065703.GB5726@vireshk-i7> References: <87bd097db7b673b1f75ca2086dfa76f4dfbf7f8c.1466058619.git.viresh.kumar@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16-06-16, 15:55, Alexandre Courbot wrote: > On 06/16/2016 03:33 PM, Viresh Kumar wrote: > >dev_pm_opp_get_sharing_cpus() returns 0 even in the case where the OPP > >core doesn't know if the table is shared or not. It is working for most > >of the platforms, as the OPP table was never created and we returned > >-ENODEV then. > > > >But in case of one of the platforms (Jetson TK1) at least, the situation > >is a bit different. The OPP table is created (somehow) before > >dev_pm_opp_get_sharing_cpus() is called and so we returned 0. The caller > >of this routine treated that as 'CPUs don't share OPPs' and that had bad > >consequences on performance. > > > >Fix this by converting 'shared_opp' to an integer and have an extra > >value when its state in undefined. dev_pm_opp_get_sharing_cpus() returns > >-EINVAL now in that case, so that the caller can handle it accordingly > >(cpufreq-dt considers that as 'all CPUs share the table'). > > > >Fixes: 6f707daa3833 ("PM / OPP: Add dev_pm_opp_get_sharing_cpus()") > >Reported-by: Alexandre Courbot > >Signed-off-by: Viresh Kumar > >--- > >Hi Alexandre, > > > >This is untested, can you please confirm if this fixes it for you? > > Yep, with this cpufreq_init() takes the fallback path and cpufreq behaves as > expected thereafter. > > Thanks for reacting so quickly! Can this go into 4.7 fixes? This will :) > Tested-by: Alexandre Courbot Thanks. -- viresh