linux-kernel - Re: [PATCH 5/7] cpufreq: balance out cpufreq_cpu_{get,put} for scaling drivers using setpolicy

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Message-ID: <CAKohpokoG16S8uft0nSFSoejipS8X=zhhg6goJs4mBSt3tAwxw@mail.gmail.com>
Date:	Wed, 6 Feb 2013 08:15:25 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Dirk Brandewie <dirk.brandewie@...il.com>
Cc:	linux-kernel@...r.kernel.org, cpufreq@...r.kernel.org,
	Dirk Brandewie <dirk.j.brandewie@...el.com>
Subject: Re: [PATCH 5/7] cpufreq: balance out cpufreq_cpu_{get,put} for
 scaling drivers using setpolicy

On 6 February 2013 07:38, Dirk Brandewie <dirk.brandewie@...il.com> wrote:
> On 02/05/2013 05:58 PM, Viresh Kumar wrote:
>>
>> On Tue, Feb 5, 2013 at 11:54 PM,  <dirk.brandewie@...il.com> wrote:
>>>
>>> From: Dirk Brandewie <dirk.brandewie@...il.com>
>>>
>>> There is an additional reference added to the driver in
>>> cpufreq_add_dev()  that is removed in__cpufreq_governor() if the
>>>
>>> driver implements target().  Remove the last reference when the
>>> driver implements setpolicy()
>>>
>>> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@...el.com>
>>>
>>> ---
>>>   drivers/cpufreq/cpufreq.c |    3 +++
>>>   1 files changed, 3 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>>> index 622e282..d17477b 100644
>>> --- a/drivers/cpufreq/cpufreq.c
>>> +++ b/drivers/cpufreq/cpufreq.c
>>> @@ -1049,6 +1049,9 @@ static int __cpufreq_remove_dev(struct device *dev,
>>> struct subsys_interface *sif
>>>
>>>          if (cpufreq_driver->target)
>>>                  __cpufreq_governor(data, CPUFREQ_GOV_STOP);
>>>
>>> +       if (cpufreq_driver->setpolicy)
>>> +               cpufreq_cpu_put(data);
>>
>>
>> I don't understand this patch at all.. I grepped both cpufreq_cpu_get() &
>> put()
>> in bleeding-edge and found everything to be correct.
>>
>> Can you please point me to the exact line numbers ?
>>
>
> Line 878 in cpufreq_add_dev()

Following is line 878:

	for_each_online_cpu(sibling) {
		struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling);
		if (cp && cpumask_test_cpu(cpu, cp->related_cpus))
			return cpufreq_add_policy_cpu(cpu, sibling, dev);
	}

How is this related to your patch?
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