Re: [PATCH v4 7/8] qcom: cpuidle: Add cpuidle driver for QCOM cpus

[Kevin Hilman <khilman@linaro.org>]

Lina Iyer <lina.iyer@linaro.org> writes:

> On Thu, Aug 21, 2014 at 03:24:44AM +0200, Daniel Lezcano wrote:
>>On 08/20/2014 12:15 AM, Lina Iyer wrote:

[...]

>>
>> So IIUC, if you specify the index 1, that means the state[0] will be
>> the default WFI. But you override the callback below in the loop.
>>
>> I recommend you use the default arm wfi callback but you implement
>> the cpu_do_idle for your platform.
>
> Yes, it was intended. I dont want to define two WFI states. The
> architectural WFI does not buy us enough compared to WFI that SoC can
> do. L2 can go into low power modes when the core is in WFI and for that
> I would like to have all WFI's enter SoC framework.

If the L2 is going into low-power, that means there will be higher
latency coming out compared to the architectural WFI, correct? 

If you have both, and the latency/residency numbers are accurate, the
governor is then left to pick the right one.  So, what's wrong with
having both?

Kevin