Re: [PATCH v2 2/2] Documentation: devicetree: Add boost-frequency binding to list boost mode frequency

Sudeep Holla
2014-02-10T10:51:37Z

On 10/02/14 07:38, Lukasz Majewski wrote:
> Hi Thomas, Sudeep,
>
>> On Fri, Feb 7, 2014 at 11:32 PM, Sudeep Holla <Sudeep.Holla@arm.com>
>> wrote:
>>> On 07/02/14 17:37, Nishanth Menon wrote:
>>>> On Fri, Feb 7, 2014 at 11:31 AM, Sudeep Holla
>>>> <Sudeep.Holla@arm.com> wrote:
>>>
>>> [...]
>>>
>>>>> Yes I think its counter-intuitive as it's visible to the
>>>>> userspace(list of frequencies and the boost parameters are
>>>>> exposed through sysfs)
>>>>
>>>> That will be a different problem -> as currently every single
>>>> frequency in the cpufreq list has ability to be marked as boost
>>>> frequency - if userspace does not maintain that, then, IMHO, fix
>>>> the userspace :D
>>>>
>>>
>>> /sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies
>>> gives the list of frequencies based on the state of the boost
>>> feature at anytime.
>>
>> The list of frequencies in
>> /sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies
>> does not change based in the state of the boost feature (enabled or
>> disabled). But the scaling_max_frequency and scaling_min_frequency are
>> updated based on the set of available + boost frequencies available.
>
> With boost intended behavior is as follow:
>
> /sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies [1]
>
> shows the non boost frequencies no matter if boost is enabled or not.
> Those are the "normal" frequencies.
>
> When boost is supported (by enabling the CONFIG_CPU_FREQ_BOOST_SW)
> extra sysfs attribute shows up:
>
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_boost_frequencies [2]
> in which are listed only the boost frequencies.
>

Correct, sorry I misunderstood this to dynamic change in
scaling_available_frequencies based on state of boot.

Regards,
Sudeep