From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Courbot Subject: Re: [PATCH] PM / OPP: 'UNKNOWN' status of opp-table->shared Date: Thu, 16 Jun 2016 15:55:11 +0900 Message-ID: References: <87bd097db7b673b1f75ca2086dfa76f4dfbf7f8c.1466058619.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87bd097db7b673b1f75ca2086dfa76f4dfbf7f8c.1466058619.git.viresh.kumar@linaro.org> Sender: linux-pm-owner@vger.kernel.org To: Viresh Kumar , Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, gnurou@gmail.com, linux-tegra@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 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? Tested-by: Alexandre Courbot