Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752310Ab3HTGfl (ORCPT ); Tue, 20 Aug 2013 02:35:41 -0400 Received: from mail-oa0-f47.google.com ([209.85.219.47]:62507 "EHLO mail-oa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752124Ab3HTGfj (ORCPT ); Tue, 20 Aug 2013 02:35:39 -0400 MIME-Version: 1.0 In-Reply-To: References: <1582060.zfvsylJcxu@vostro.rjw.lan> Date: Tue, 20 Aug 2013 12:05:39 +0530 Message-ID: Subject: Re: [PATCH V2 07/11] cpufreq: Use cpufreq_policy_list for iterating over policies From: Viresh Kumar To: "Rafael J. Wysocki" Cc: Lists linaro-kernel , Patch Tracking , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , "Srivatsa S. Bhat" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1549 Lines: 41 On 19 August 2013 16:57, Viresh Kumar wrote: > It wasn't my patch actually.. It only made it visible that's it :) > The problem is: > - On suspend all CPUs are removed and so governors are > stopped. > - On resume, handle_update() is called for the boot cpu and > cpu_add_dev for all others. > > handle_update() doesn't start governor but only plays with > CPUFREQ_GOV_LIMITS.. when we start adding other > CPUs and call: cpufreq_add_policy_cpu() which fails in > following call: > > __cpufreq_governor(policy, CPUFREQ_GOV_STOP); > > and so cpufreq_policy_cpu never gets initialized to > policy->cpu and stays at -1, and hence the crash. > > So, there are few problems with core at this point: > - I don't understand how does the work done in > cpufreq_add_dev() gets done for boot cpu during > resume ? And so how does Srivatsa's "frozen" solution > really works (I haven't had time to investigate, its not > that I couldn't understand it :) ).. > > - We need to start governor boot cpu in handle_update() > and things would be solved... Whatever I wrote here was simply _Bullshit_ :( I am about to send you a fixup patchset that fixes this issue, and yes it was my patch which introduced this problem :(, but because of some mishandling of cpufreq_policy_list :) -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/