From mboxrd@z Thu Jan  1 00:00:00 1970
From: Harry van Haaren <harryhaaren@gmail.com>
Subject: Re: CpuFreq Laptop Scaling broken?
Date: Wed, 27 Aug 2014 15:53:52 +0100
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Cc: linux-rt-users@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
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To: Viresh Kumar <viresh.kumar@linaro.org>
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On Tue, Aug 26, 2014 at 11:44 PM, Harry van Haaren
<harryhaaren@gmail.com> wrote:
> On Tue, Aug 26, 2014 at 5:34 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>> The functions  of interest would be, drivers/cpufreq/cpufreq.c:
>> - static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
>> - static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
>> const char *buf, size_t count)
>>
>> Try to add some prints there while returning errors and then try to change
>> governor from userspace and things might get somewhat better then..
>
> Thanks for the suggestion, I'll update once I have more info

Found a little time to check this: the cpufreq_get_policy() call
returns non-zero:

static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
                    const char *buf, size_t count)
{
    int ret;
    char    str_governor[16];
    struct cpufreq_policy new_policy;

  printk( "RT debug: store_scaling_governor() with %s\n", buf );

    ret = cpufreq_get_policy(&new_policy, policy->cpu);
    if (ret)
  {
    printk( "RT debug: ERROR: get policy() returned \n" );
        return ret;
  }


dmesg:
[   43.186804] RT debug: store_scaling_governor() with performance
[   43.186811] RT debug: ERROR: get policy() returned


This output is from a fresh boot: so it seems that the getting the
current policy after
a boot isn't functioning right here.