From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eduardo Valentin <eduardo.valentin@ti.com>
Subject: Re: [PATCH v2 4/4] ARM:TMU:fix: Avoid lockup when first frequency
 table entry is CPUFREQ_ENTRY_INVALID
Date: Thu, 25 Apr 2013 11:39:12 -0400
Message-ID: <51794E20.9010107@ti.com>
References: <1366389493-8239-1-git-send-email-l.majewski@samsung.com> <1366893045-31586-1-git-send-email-l.majewski@samsung.com> <1366893045-31586-5-git-send-email-l.majewski@samsung.com> <51794785.6090406@ti.com> <20130425172246.2143525e@amdc308.digital.local>
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To: Lukasz Majewski <l.majewski@samsung.com>
Cc: Eduardo Valentin <eduardo.valentin@ti.com>, Kukjin Kim <kgene.kim@samsung.com>, "devicetree-discuss@lists.ozlabs.org" <devicetree-discuss@lists.ozlabs.org>, Zhang Rui <rui.zhang@intel.com>, "linux-samsung-soc@vger.kernel.org" <linux-samsung-soc@vger.kernel.org>, Linux PM list <linux-pm@vger.kernel.org>, Amit Daniel Kachhap <amit.kachhap@linaro.org>, Tomasz Figa <t.figa@samsung.com>, Sachin Kamat <sachin.kamat@linaro.org>, Myungjoo Ham <myungjoo.ham@samsung.com>, Kyungmin Park <kyungmin.park@samsung.com>
List-Id: linux-pm@vger.kernel.org

On 25-04-2013 11:22, Lukasz Majewski wrote:
> Hi Eduardo,
>
>> Lukasz,
>>
>> On 25-04-2013 08:30, Lukasz Majewski wrote:
>>> With the while loop, when i=0 and first entry in the frequency
>>> table is CPUFREQ_ENTRY_INVALID, the code results in an endless loop
>>> (since i is not incremented).
>>>
>>> To fix this problem the for loop has been chosen. Incrementing i in
>>> the for end block solves the problem.
>>>
>>> Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
>>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>>> ---
>>> Changes for v2:
>>> - New in v2
>>
>> This patch wont apply on Rui's tree.
>>
>> I believe this has been already fixed on Rui's tree (next branch).
>> Could you please check if the commit below fix your issue:
>> git.kernel.org/cgit/linux/kernel/git/rzhang/linux.git/commit/?h=thermal&id=fc35b35cbe24ef021ea9acfba21e54da958df747
>>
>> commit fc35b35cbe24ef021ea9acfba21e54da958df747
>> Author: Zhang Rui <rui.zhang@intel.com>
>> Date:   Fri Feb 8 13:09:32 2013 +0800
>>
>>       Thermal: cpufreq cooling: fix parsing per_cpu
>> cpufreq_frequency_table
>>
>
> Thanks for pointing out. It seems, that this function fixes this
> problem.

OK.

>
> As a side note, is this problem fixed at stable kernels?

Good question, probably not!

>
>>
>>
>>> ---
>>>    drivers/thermal/cpu_cooling.c |    3 +--
>>>    1 file changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/thermal/cpu_cooling.c
>>> b/drivers/thermal/cpu_cooling.c index 8dc44cb..df79f5e8 100644
>>> --- a/drivers/thermal/cpu_cooling.c
>>> +++ b/drivers/thermal/cpu_cooling.c
>>> @@ -124,7 +124,7 @@ static unsigned int get_cpu_frequency(unsigned
>>> int cpu, unsigned long level) if (!table)
>>>    		return ret;
>>>
>>> -	while (table[i].frequency != CPUFREQ_TABLE_END) {
>>> +	for (; table[i].frequency != CPUFREQ_TABLE_END; i++) {
>>>    		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
>>>    			continue;
>>>
>>> @@ -138,7 +138,6 @@ static unsigned int get_cpu_frequency(unsigned
>>> int cpu, unsigned long level) /*return if level matched and table
>>> in descending order*/ if (descend && i == level)
>>>    			return table[i].frequency;
>>> -		i++;
>>>    	}
>>>    	i--;
>>>
>>>
>
>
>