[PATCH v2 00/12] CPU idle for Armada XP

Gregory CLEMENT gregory.clement at free-electrons.com
Fri Sep 13 07:17:17 EDT 2013


On 13/09/2013 13:00, Andrew Lunn wrote:
> 
> On Fri, Sep 13, 2013 at 12:06:29PM +0200, Gregory CLEMENT wrote:
>> Hello,
>>
>> This patch set adds the CPU idle support for Armada XP and prepares
>> the support for Armada 370. This was based on the work of Nadav
>> Haklai.
> 
> Hi Gregory.
> 
> Kirkwood has the ability to put the DDR into self refresh mode, which
> is used as part of the second level idle mode. Does 370/XP have this?

Indeed there is a self refresh bit on a DDR related register. I thought
this kind of feature is more likely used for suspend to ram.

We plan to also submit the suspend to ram but not immediately.

> 
> For XP, with it being SMP, it would be a bit more complex, since you
> would not want to use it unless all CPUs were idle.

I wonder how the others SMP ARM SoCs deal with it, I hope this time
there will be a framework available and we won't have to create it! ;)

> 
>       Thanks
> 	Andrew
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com



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