From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: sedat.dilek@gmail.com
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
Dirk Brandewie <dirk.brandewie@gmail.com>,
Dirk Brandewie <dirk.j.brandewie@intel.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org,
cpufreq@vger.kernel.org, Linux PM list <linux-pm@vger.kernel.org>,
Lists linaro-kernel <linaro-kernel@lists.linaro.org>,
Nathan Zimmer <nzimmer@sgi.com>
Subject: Re: linux-next: Tree for Apr 9 [cpufreq: NULL pointer deref]
Date: Wed, 17 Apr 2013 18:14:55 +0200 [thread overview]
Message-ID: <3689306.YZQlEiUYft@vostro.rjw.lan> (raw)
In-Reply-To: <CA+icZUVsNG66_v8QA17LQ27z1tjRjDqzB148OSV9WQP0_NkRKA@mail.gmail.com>
On Wednesday, April 17, 2013 04:04:46 PM Sedat Dilek wrote:
> On Mon, Apr 15, 2013 at 7:22 PM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > On 15 April 2013 21:37, Dirk Brandewie <dirk.brandewie@gmail.com> 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 <viresh.kumar@linaro.org>
> > 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 <viresh.kumar@linaro.org>
> > ---
> > 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.
next prev parent reply other threads:[~2013-04-17 16:14 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CA+icZUU_K9PiFMqMsOEk1+c2DX8LrUojZptPiRVarv4dcB2qFA@mail.gmail.com>
2013-04-09 14:03 ` linux-next: Tree for Apr 9 [cpufreq: NULL pointer deref] Rafael J. Wysocki
2013-04-09 14:04 ` Sedat Dilek
2013-04-09 14:56 ` Viresh Kumar
2013-04-09 14:59 ` Sedat Dilek
2013-04-09 16:08 ` Sedat Dilek
2013-04-09 16:51 ` Viresh Kumar
2013-04-09 16:57 ` Sedat Dilek
2013-04-09 18:26 ` Sedat Dilek
2013-04-09 18:29 ` Sedat Dilek
2013-04-09 18:39 ` Sedat Dilek
2013-04-09 20:26 ` Sedat Dilek
2013-04-10 5:41 ` Sedat Dilek
2013-04-10 5:53 ` Sedat Dilek
2013-04-10 6:14 ` Sedat Dilek
2013-04-12 8:23 ` Viresh Kumar
2013-04-12 14:24 ` Sedat Dilek
2013-04-12 15:45 ` Sedat Dilek
2013-04-12 16:27 ` Sedat Dilek
2013-04-12 21:08 ` Sedat Dilek
2013-04-12 22:51 ` Rafael J. Wysocki
2013-04-13 9:55 ` Sedat Dilek
2013-04-15 16:07 ` Dirk Brandewie
2013-04-15 16:13 ` Sedat Dilek
2013-04-15 17:22 ` Viresh Kumar
2013-04-15 17:51 ` Sedat Dilek
2013-04-15 17:57 ` Sedat Dilek
2013-04-15 18:07 ` Sedat Dilek
2013-04-15 18:01 ` Dirk Brandewie
2013-04-17 14:04 ` Sedat Dilek
2013-04-17 16:14 ` Rafael J. Wysocki [this message]
2013-04-21 23:30 ` Rafael J. Wysocki
2013-04-22 3:14 ` Viresh Kumar
2013-04-22 12:00 ` Rafael J. Wysocki
2013-04-15 17:27 ` Nathan Zimmer
2013-04-15 17:42 ` Dirk Brandewie
2013-04-15 18:05 ` Nathan Zimmer
2013-04-09 14:59 ` Viresh Kumar
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