From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH] cpufreq: scpi/scmi: Fix freeing of dynamic OPPs Date: Fri, 4 Jan 2019 11:01:42 +0000 Message-ID: <20190104110142.GA28483@e107155-lin> References: <7dddbeabb434225d9b3d02600ea4a2313622ca26.1546594910.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <7dddbeabb434225d9b3d02600ea4a2313622ca26.1546594910.git.viresh.kumar@linaro.org> Sender: stable-owner@vger.kernel.org To: Viresh Kumar Cc: Valentin Schneider , "Rafael J. Wysocki" , Nishanth Menon , Stephen Boyd , linux-pm@vger.kernel.org, Vincent Guittot , quentin.perret@arm.com, dietmar.eggemann@arm.com, Sudeep Holla , Douglas.Raillard@arm.com, "4 . 20" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-pm@vger.kernel.org On Fri, Jan 04, 2019 at 03:14:33PM +0530, Viresh Kumar wrote: > Since the commit 2a4eb7358aba ("OPP: Don't remove dynamic OPPs from > _dev_pm_opp_remove_table()"), dynamically created OPP aren't > automatically removed anymore by dev_pm_opp_cpumask_remove_table(). This > affects the scpi and scmi cpufreq drivers which no longer free OPPs on > failures or on invocations of the policy->exit() callback. > > Create a generic OPP helper dev_pm_opp_remove_all_dynamic() which can be > called from these drivers instead of dev_pm_opp_cpumask_remove_table(). > > In dev_pm_opp_remove_all_dynamic(), we need to make sure that the > opp_list isn't getting accessed simultaneously from other parts of the > OPP core while the helper is freeing dynamic OPPs, i.e. we can't drop > the opp_table->lock while traversing through the OPP list. And to > accomplish that, this patch also creates _opp_kref_release_unlocked() > which can be called from this new helper with the opp_table lock already > held. > I did test it but since I couldn't reproduce the original issue, my tested-by is not that worth. Anyways the changes look fine to me. Reviewed-by: Sudeep Holla