using cpuidle on panda board

[Andy Green]

On 01/13/2012 08:34 PM, Somebody in the thread at some point said:

(adding AmitK)

Amit, do you know of a good place to raid for better cpuidle, closer to 
upstream than OZ?

-Andy

> On 13 January 2012 12:12, Jassi Brar<jaswinder.singh at linaro.org>  wrote:
>> On 13 January 2012 16:13, Andy Green<andy.green at linaro.org>  wrote:
>>> On 01/13/2012 05:59 PM, Somebody in the thread at some point said:
>>>>
>>>> Hi,
>>>>
>>>> I'd like to do some tests with cpuidle on my panda board but i'm
>>>> facing some issues:
>>>>
>>>> Originally, i'd like to use the Linaro developer image which uses the
>>>> landing team branch tilt-linux-linaro-3.1 but the omap4 cpuidle driver
>>>> only works when cpu1 is off whereas i'd like to do some test with both
>>>> cpus.
>>>> The android kernel has got a cpuidle driver which can enter C-states
>>>> when both cpus are running and I was wondering if there is a plan to
>>>> merge this driver into the tilt-linux-linaro-x.x branch ? maybe in 3.2
>>>> ?
>>>>
>>>> Then, when I'm testing the landing-panda-11.12-release android image
>>>> on my panda board revA1, the cpuidle is using only C0 state (WFI)
>>>> according to cpuidle stats.
>>>>
>>>> My test sequence:
>>>> prevent suspend with: echo qwerty>    /sys/power/wake_lock
>>>> let android enter the early_suspend mode
>>>> get cpuidle statistics on cpu0 et cpu1 in cpuidle/stateX/time : only
>>>> state0 time is different from 0
>>>>
>>>> Is it a normal behavior ?
>>>
>>>
>>> No I think cpuidle is broken with what we have in tilt-3.1.
>>>
>>> It's worth trying tilt-tracking which, last time Jassi looked at it was
>>> working and visiting all the C states.
>>>
>> IIRC, CPU_0 entered C1, C2 states only when the CPU_1 is offline, when I tested.
>>
> yes, but I need to keep both cpu online for my tests with sched_mc
>
>> Vincent, would you remember exactly which android branch has it working with
>> both cpus online?
>>
>
> I'm using the the compiled baseline :
> https://android-build.linaro.org/builds/~linaro-android/landing-panda-11.12-release/#build=3
> For this baseline, a cpuidle device is registered for each CPU (0,1)
> unlike the tilt tracking which register a device only for cpu0.
> This baseline uses an other cpuidle driver for omap4 which manages both CPU
>
> Vincent
>
>> Cheers,
>> Jassi


-- 
Andy Green | TI Landing Team Leader
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