[PATCH v11 4/6] ARM: Exynos: switch to using generic cpufreq driver for Exynos4210/5250/5420

Viresh Kumar viresh.kumar at linaro.org
Tue Nov 25 03:02:10 PST 2014


On 24 November 2014 at 19:14, Sudeep Holla <sudeep.holla at arm.com> wrote:
> On 20/11/14 03:48, Viresh Kumar wrote:
>> - I believe CPUs boot in the order they are present in DT except for the
>> boot CPU. So, the first node for every cluster should have it.
>>
>> Correct ? Then we can update the fixme.
>>
>
> No, I disagree as you trying to implicitly depend on the logic Linux uses to
> assign logical index. It can be changed any time, and depending
> on it might break things in future which can't be fixed easily later
> especially if it's DT related.

Yeah, correct.

>> Hmm, I never thought about it. But yes the CPU with the OPPs should
>> be the first one to come back.
>>
>
> How can you assume that ? I can write a simple test which hot-plugs out
> all the CPUs in the (esp. multi-cluster) system in ascending order of
> logical index and hot-plug back in descending order. Then the above
> logic fails.

What I said is: Yes the CPU with the OPPs should be the first one to come
back, if this has to work correctly. Otherwise it will break..

And you repeated the same :)

> The platforms needing it have to get involved in such discussions to
> make any progress.

Yes there were people involved. I hope I cc'd you as well...



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