From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753343Ab2GTKFK (ORCPT ); Fri, 20 Jul 2012 06:05:10 -0400 Received: from ogre.sisk.pl ([193.178.161.156]:49451 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753225Ab2GTKFH (ORCPT ); Fri, 20 Jul 2012 06:05:07 -0400 From: "Rafael J. Wysocki" To: MyungJoo Ham Subject: Re: [RESEND PATCH] [CPUFREQ] EXYNOS: bugfix on retrieving old_index from freqs.old Date: Fri, 20 Jul 2012 12:10:47 +0200 User-Agent: KMail/1.13.6 (Linux/3.5.0-rc5+; KDE/4.6.0; x86_64; ; ) Cc: linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, Jonghwa Lee References: <1342752842-21368-1-git-send-email-myungjoo.ham@samsung.com> In-Reply-To: <1342752842-21368-1-git-send-email-myungjoo.ham@samsung.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-Id: <201207201210.48030.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, July 20, 2012, MyungJoo Ham wrote: > From: Jonghwa Lee > > The policy might have been changed since last call of target(). > Thus, using cpufreq_frequency_table_target(), which depends on > policy to find the corresponding index from a frequency, may return > inconsistent index for freqs.old. Thus, old_index should be > calculated not based on the current policy. > > We have been observing such issue when scaling_min/max_freq were > updated and sometimes cuased system lockups deu to incorrectly > configured voltages. > > Signed-off-by: MyungJoo Ham Applied to the pm-cpufreq branch of the linux-pm.git tree, will be pushed for v3.6. Thanks, Rafael > --- > drivers/cpufreq/exynos-cpufreq.c | 14 ++++++++++++-- > 1 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/exynos-cpufreq.c b/drivers/cpufreq/exynos-cpufreq.c > index b243a7e..af2d81e 100644 > --- a/drivers/cpufreq/exynos-cpufreq.c > +++ b/drivers/cpufreq/exynos-cpufreq.c > @@ -62,8 +62,18 @@ static int exynos_target(struct cpufreq_policy *policy, > goto out; > } > > - if (cpufreq_frequency_table_target(policy, freq_table, > - freqs.old, relation, &old_index)) { > + /* > + * The policy max have been changed so that we cannot get proper > + * old_index with cpufreq_frequency_table_target(). Thus, ignore > + * policy and get the index from the raw freqeuncy table. > + */ > + for (old_index = 0; > + freq_table[old_index].frequency != CPUFREQ_TABLE_END; > + old_index++) > + if (freq_table[old_index].frequency == freqs.old) > + break; > + > + if (freq_table[old_index].frequency == CPUFREQ_TABLE_END) { > ret = -EINVAL; > goto out; > } >