[PATCH] ARM: EXYNOS: mcpm: Don't rely on firmware's secondary_cpu_start

Kukjin Kim kgene.kim at samsung.com
Wed Jun 11 08:28:15 PDT 2014


On 06/12/14 00:19, Doug Anderson wrote:
> Chander,
>
> On Tue, Jun 10, 2014 at 9:52 PM, Chander Kashyap<k.chander at samsung.com>  wrote:
>> Hi Doug,
>>
>> On Tue, Jun 10, 2014 at 9:19 PM, Nicolas Pitre<nicolas.pitre at linaro.org>  wrote:
>>> On Tue, 10 Jun 2014, Doug Anderson wrote:
>>>
>>>> My S-state knowledge is not strong, but I believe that Lorenzo's
>>>> questions matter if we're using S2 for CPUidle (where we actually turn
>>>> off power and hot unplug CPUs) but not when we're using S1 for CPUidle
>>>> (where we just enter WFI/WFE).
>>>>
>>
>> No Its not plain WFI.
>>
>> All cores in Exynos5420 can be powered off independently.
>> This functionality has been tested.
>>
>> Below is the link for the posted patches.
>>
>> https://lkml.org/lkml/2014/6/10/194
>>
>> And as Nicolas wrote, these patches need MCPM for that.
>
> Most excellent!  I should have been more clear that I only knew about
> how CPUidle worked in our local production kernel.  There I'm pretty
> sure CPUidle is just WFI/WFE.  If you've got patches to do better then
> that's great!
>
> ...can you confirm that my patch doesn't interfere with your improved
> CPUidle?  It's been Acked by Nicolas (thanks!) so I'd imagine it will
> land shortly.  Kukjin: I assume you'll be taking this?
>
Sure, I will ;-)

Thanks,
Kukjin



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