[PATCH v7 0/6] cpufreq: use generic cpufreq drivers for exynos platforms

Tobias Jakobi liquid.acid at gmx.net
Sat Jul 19 14:17:25 PDT 2014


Tomasz Figa wrote:
> Tobias,
> 
> On 19.07.2014 21:20, Tobias Jakobi wrote:
>> Hello,
>>
>> I have a question concerning an older version of this patchset, the one
>> which still included exynos4x12 support and where the clocking data was
>> provided through DT.
>>
>> I tried to get this working for my ODROID-X2, which does work well,
>> including the usage of the boost frequences. Since the X2 has an
>> Exynos4412 Prime I added additional clocking data and operating points.
>>
>> clocking data (comes from the vendor kernel):
>> <1704000 3 7 0 6 1 2 7 0 7>
>> <1600000 3 7 0 6 1 2 6 0 7>
>>
>> operating points (again from vendor kernel):
>> 1704000 1375000
>> 1600000 1350000
>>
>> Doing this I get correct output from scaling_available_frequencies and
>> scaling_boost_frequencies and the driver seems to select these
>> frequences. However when reading from cpufreq_cur_freq, which I think
>> returns the frequency of the armclk, the maximum freq never exceeds
>> 1.5GHz. So effectively the additional clocking data and opps are not used.
>>
>> I wonder this happens? Is there some kind of limit enforced?
> 
> Have you also extended the array of allowed APLL settings in
> drivers/clk/clk-exynos4.c?
> 
> Best regards,
> Tomasz
> 

Thanks Tomasz, that did the trick!


With best wishes,
Tobias




More information about the linux-arm-kernel mailing list