Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756344AbaD1U5k (ORCPT ); Mon, 28 Apr 2014 16:57:40 -0400 Received: from smtp1.it.da.ut.ee ([193.40.5.66]:33025 "EHLO smtp1.it.da.ut.ee" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751408AbaD1U5i (ORCPT ); Mon, 28 Apr 2014 16:57:38 -0400 Date: Mon, 28 Apr 2014 23:57:34 +0300 (EEST) From: Meelis Roos To: "Srivatsa S. Bhat" cc: rjw@rjwysocki.net, viresh.kumar@linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/5] Cpufreq frequency serialization fixes In-Reply-To: <20140428185331.28755.899.stgit@srivatsabhat.in.ibm.com> Message-ID: References: <20140428185331.28755.899.stgit@srivatsabhat.in.ibm.com> User-Agent: Alpine 1.00 (SOC 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Meelis Roos reported hangs during boot in the longhaul cpufreq driver, after > commit 12478cf0c55 (cpufreq: Make sure frequency transitions are serialized). > The root-cause of this issue is the extra invocation of the > cpufreq_freq_transition_begin() and cpufreq_freq_transition_end() APIs in the > longhaul driver. I found similar issues in the powernow-k6 and powernow-k7 > drivers as well. This patchset fixes the issue in all the 3 drivers and also > adds a debug infrastructure to catch such issues easily. > > Patches 1-4 fix the regression in longhaul, powernow-k6 and powernow-k7 > drivers. (Patch 2 fixes a different bug in powernow-k6, and it is kept as a > separate patch instead of merging it with patch 3, because I felt that it was > a bit subtle and needed attention in a separate patch). > > Patch 5 adds a debug infrastructure to the cpufreq core to catch such problems > more easily in the future. > > > Changes in v2: > -------------- > > * Modified patch 1 to take error returns into account, as pointed out by > Viresh. > * Added patch 2 to fix the existing issue in the powernow-k6 driver, pointed > out by Viresh. > * Added patch 5 to introduce a debug infrastructure to catch such issues > easily. This also works on my VIA EPIA. -- Meelis Roos (mroos@linux.ee) -- 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/