Re: [PATCH 1/2] cpufreq: Add governor operation ongoing flag

From: Xiaoguang Chen
Date: Wed Aug 14 2013 - 04:50:52 EST


2013/8/14 Viresh Kumar <viresh.kumar@xxxxxxxxxx>:
> On 14 August 2013 13:49, Xiaoguang Chen <chenxg.marvell@xxxxxxxxx> wrote:
>> Yes, "START (If STOP passed)", this is important, we don't have this
>> patch on our code base, So even Process B's STOP failed(as governor
>> enable flag is set to false by process A already ), it can still do
>> START operation, So my problem occurs.
>> My problem is that I see ondemand governor is started twice during
>> frequent governor switch and cpu hotplug stress test.
>>
>> The After seeing your patch for the return value checking, I think my
>> problem should not occur.
>> This issue really botherred me for a long time. :(
>
> Exactly, the problem was users of this API were abusing it as they didn't
> cared for its return value. I hope that is fixed widely now and in case
> some places are still left, they should be fixed as well.
>
> --
> viresh


Hi, Viresh
After checking your patch, I find that __cpufreq_set_policy function
doesn't check STOP and EXIT 's return value
is it on purpose? if not, I can provide a patch to add it.

Thanks
Xiaoguang
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