Re: CPUIdle for Exynos5422 Odroid-XU3/XU4 boards.

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 08/20/2015 08:15 PM, Anand Moon wrote:
> Hi Daniel,
>
> On 20 August 2015 at 21:40, Daniel Lezcano <daniel.lezcano@free.fr> wrote:
>> On 08/20/2015 12:54 PM, Anand Moon wrote:
>>>
>>> Hello Krzysztof/Kukjim,
>>>
>>> CPUIdle seen to be not working for Exynos5422 Odroid boards.
>>>
>>> Is their any way this feature will be implemented in the future.
>>
>>
>> Yeah a good willing to fix the bl1. More than one year asking for that !
>> nooo way !!
>>
>> Your answer is at the end of
>> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/350632.html
>>
>>
>
> Thanks for the explanation.
>
> I was just referring following the source code.
>
> https://github.com/hardkernel/linux/blob/odroidxu3-3.10.y/arch/arm/mach-exynos/cpuidle-exynos5422.c

Ah, thanks for the pointer. So for my information, is that driver not 
working with the exynos5422 ?

> It seem that cpufreq and cpuidle go hand in hand.

At the first glance, there is a dependency with the cluster power state. 
It is not allowed to enter the cluster power down if another subsystem 
deny it. The driver itself is a pack of hacks based on cpuidle legacy 
code and wildly backported from older kernels with arbitrary latency and 
residency values.


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