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MX53 GPC/DVFS how to use?

Question asked by left on Feb 7, 2013
Latest reply on Aug 22, 2013 by Wigros Sun
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Hi all,

 

I am working on MX53 power consumption based on android bsp 10.3. I would like to use DVFS to minimize the power consumption in idle state.

I am not sure how the GPC works with DVFS. Please correct me if I am wrong.

 

From my understanding, GPC takes the lead of the flow. Once an GPC interrupt is triggered (I don't know who trigger the interrupt and how.), dvfs_irq(...) is called and then it schedules a delayed routine call dvs_core_work_handler(...). The delayed routine would tune up/down the core frequency based on the setpoint provided.

 

However, following the code, I have enabled GPC interrupt and DVFS. But no GPC interrupt is triggered after the kernel start.

Here is the result of "sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state"

 

cat time_in_state

400000 0

800000 0

1000000 95956

 

The system kept running at 1GHz.

What should I do if I want the cpu runs at 400MHz in idle mode?

 

Regards,

CPKwok

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