Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965581Ab3DQQHH (ORCPT ); Wed, 17 Apr 2013 12:07:07 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:35589 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965231Ab3DQQHE (ORCPT ); Wed, 17 Apr 2013 12:07:04 -0400 From: "Rafael J. Wysocki" To: sedat.dilek@gmail.com Cc: Viresh Kumar , Dirk Brandewie , Dirk Brandewie , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, Linux PM list , Lists linaro-kernel , Nathan Zimmer Subject: Re: linux-next: Tree for Apr 9 [cpufreq: NULL pointer deref] Date: Wed, 17 Apr 2013 18:14:55 +0200 Message-ID: <3689306.YZQlEiUYft@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0-rc6+; KDE/4.9.5; x86_64; ; ) In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4582 Lines: 119 On Wednesday, April 17, 2013 04:04:46 PM Sedat Dilek wrote: > On Mon, Apr 15, 2013 at 7:22 PM, Viresh Kumar wrote: > > On 15 April 2013 21:37, Dirk Brandewie wrote: > >> If the intel_pstate driver is being used __cpufreq_governor() should NOT be > >> called intel_pstate does not implement the target() callback. > >> > >> Nathan's commit 5800043b2 changed the fence around the call to > >> __cpufreq_governor() in __cpufreq_remove_dev() here is the relevant hunk. > > > > No it isn't. > > > >> + if (has_target) > >> __cpufreq_governor(data, CPUFREQ_GOV_STOP); > > > > As it has taken care of this limitation. > > > > BUT some of my earlier patches haven't. :( > > Here is the fix (Sedat please try this and give your tested-by, use the attached > > patch as gmail might break what i am copying in mail).. > > > > Sorry for being late in fixing this issue, i am still down with Tonsil infection > > and fever.. Today only i got some power to fix it after seeing Dirk's mail. > > > > Your tested-by may help me to recover quickly :) > > > > @Rafael: I will probably be down for one more week and so not doing any > > reviews for now... I do check important mails sent directly to me though. > > > > Hi Viresh, > > can you sent a separate patch on this (with Reported/Tested-by#s)? > AFAICS this is not in pm.git#linux-next? That's because I'm traveling and not pushing things to the tree. I'll start doing that again on Saturday. Till then, please apply the Viresh's patch on top of linux-next. Thanks, Rafael > > ------------x----------------------x------------------ > > > > From: Viresh Kumar > > Date: Mon, 15 Apr 2013 22:43:57 +0530 > > Subject: [PATCH] cpufreq: Don't call __cpufreq_governor() for drivers without > > target() > > > > Some cpufreq drivers implement their own governor and so don't need us to call > > generic governors interface via __cpufreq_governor(). Few recent commits haven't > > obeyed this law well and we saw some regressions. > > > > This patch tries to fix this issue. > > > > Signed-off-by: Viresh Kumar > > --- > > drivers/cpufreq/cpufreq.c | 18 +++++++++++++----- > > 1 file changed, 13 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > index 3564947..a6f6595 100644 > > --- a/drivers/cpufreq/cpufreq.c > > +++ b/drivers/cpufreq/cpufreq.c > > @@ -858,13 +858,18 @@ static int cpufreq_add_policy_cpu(unsigned int > > cpu, unsigned int sibling, > > struct device *dev) > > { > > struct cpufreq_policy *policy; > > - int ret = 0; > > + int ret = 0, has_target = 0; > > unsigned long flags; > > > > policy = cpufreq_cpu_get(sibling); > > WARN_ON(!policy); > > > > - __cpufreq_governor(policy, CPUFREQ_GOV_STOP); > > + rcu_read_lock(); > > + has_target = !!rcu_dereference(cpufreq_driver)->target; > > + rcu_read_unlock(); > > + > > + if (has_target) > > + __cpufreq_governor(policy, CPUFREQ_GOV_STOP); > > > > lock_policy_rwsem_write(sibling); > > > > @@ -877,8 +882,10 @@ static int cpufreq_add_policy_cpu(unsigned int > > cpu, unsigned int sibling, > > > > unlock_policy_rwsem_write(sibling); > > > > - __cpufreq_governor(policy, CPUFREQ_GOV_START); > > - __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); > > + if (has_target) { > > + __cpufreq_governor(policy, CPUFREQ_GOV_START); > > + __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); > > + } > > > > ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); > > if (ret) { > > @@ -1146,7 +1153,8 @@ static int __cpufreq_remove_dev(struct device > > *dev, struct subsys_interface *sif > > > > /* If cpu is last user of policy, free policy */ > > if (cpus == 1) { > > - __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); > > + if (has_target) > > + __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); > > > > lock_policy_rwsem_read(cpu); > > kobj = &data->kobj; -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/