Re: [cpufreq] WARNING: at kernel/lockdep.c:2739 lockdep_trace_alloc()

From: Viresh Kumar
Date: Mon Feb 11 2013 - 04:10:47 EST

On 11 February 2013 14:22, Fengguang Wu <fengguang.wu@xxxxxxxxx> wrote:
> Greetings,

Hi Fengguang,

> I got the below oops and the first bad commit is
> commit 50f6802f8dccb7bbad29010e57973d46b7e7a07e
> Author: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Date: Thu Feb 7 10:55:00 2013 +0530

There is something really wrong. This problem was earlier reported
and was fixed immediately. And shouldn't be there with linux-next
branch of Rafael.

What tree are you working on ?

Even in linux-next/master i see above commit as:

commit 2eaa3e2df185997e92596ab14a2a67dde3876d2e
Author: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Date: Thu Feb 7 10:55:00 2013 +0530

cpufreq: Fix locking issues

cpufreq core uses two locks:
- cpufreq_driver_lock: General lock for driver and cpufreq_cpu_data array.
- cpu_policy_rwsemfix locking: per CPU reader-writer semaphore
designed to cure
all cpufreq/hotplug/workqueue/etc related lock issues.

These locks were not used properly and are placed against their principle
(present before their definition) at various places. This patch is
an attempt to
fix their use.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
drivers/cpufreq/cpufreq.c | 72
1 file changed, 38 insertions(+), 34 deletions(-)

Which would certainly fix your problem.
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