[RFC][PATCH 0/7] OMAP4 cpuidle cleanup

Daniel Lezcano daniel.lezcano at linaro.org
Wed Mar 21 06:43:29 EDT 2012


On 03/21/2012 10:56 AM, Santosh Shilimkar wrote:
> On Wednesday 21 March 2012 03:21 PM, Daniel Lezcano wrote:
>> On 03/21/2012 10:36 AM, Shilimkar, Santosh wrote:
>>> On Wed, Mar 21, 2012 at 2:57 PM, Daniel Lezcano
>>> <daniel.lezcano at linaro.org>   wrote:
>>>> This patchset is a proposition to improve a bit the code.
>>>> The changes are code cleanup and does not change the behavior of the
>>>> driver itself.
>>>>
>>> Thanks. Will have a look at your series.
>>
>> Cool, thanks.
>>
>>>> A couple a things call my intention. Why the cpuidle device is set
>>>> for cpu0 only
>>> Because the mainline code CPUIDLE is supported along with CPUhotplug.
>>> This is going to change though with Couple CPUIDLE and corresponding
>>> OMAP updates.
>>
>> Ok, thanks for the information. I will look deeper. What happens to cpu1
>> when it is online and has nothing to do ?
>>
>>>> and why the WFI is not used ?
>>>>
>>> I didn't get this question. Do you mean the generic WFI?
>>
> I execute default idle loop.

So is it not possible to add a cpuidle device for cpu1 and define only 
one state for the 'wfi-for-omap' ?

>> yes.
>>
>>> If yes, then, it's mainly because OMAP need additional
>>> custom barriers.
>>
>> Ah, ok. I am not sure if it is possible but that may be cool if we can
>> call cpu_do_idle instead with additional barrier.
>>
> There is no need. Since code around WFI is customised, it make no sense
> to call cpu_do_idle(0 ofr only that instruction sake.

For my personal information, why the WFI is customised for omap4 ?

Thanks
   -- Daniel



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