[Query] CPUFreq: Does these machines have separate clock domains for CPUs?
Magnus Damm
magnus.damm at gmail.com
Wed Sep 4 03:27:37 EDT 2013
Hi Viresh,
On Fri, Aug 30, 2013 at 4:33 PM, Viresh Kumar <viresh.kumar at linaro.org> wrote:
> On 30 August 2013 12:18, Magnus Damm <magnus.damm at gmail.com> wrote:
>> Hi Viresh,
>>
>> On Thu, Aug 29, 2013 at 7:15 PM, Viresh Kumar <viresh.kumar at linaro.org> wrote:
>>> Hi,
>>>
>>> I have been doing some CPUFreq cleanup work and
>>> wanted to know if the below mentioned machines have separate
>>> clock domains for their CPUs or all share the same domain?
>>>
>>> So, that we can use some generic routines for these drivers which
>>> would eventually do:
>>>
>>> cpumask_setall(policy->cpus);
>>>
>>> And I wanted to make sure that this doesn't break them.. :)
>>>
>>> ......
>>>
>>> The drivers are:
>> ...
>>> drivers/cpufreq/sh-cpufreq.c
>> ...
>>
>> The above SH cpufreq driver seems to be written with SMP in mind, but
>> I would say SMP is a very rare case for SH. So I believe it can be
>> considered as UP-only at this point. If Paul disagrees I'm quite sure
>> he will tell us.
>
> Okay.. The problem isn't really SMP but different clock domains for CPUs
> in a SMP system..
>
> So, even if we have a SMP SH machine, will it have same clock line for
> all CPUs?
Yeah, I understand your question but I'm afraid that I don't know the
answer myself.
> I will go with the change anyway..
Good plan. Thanks for cleaning up the cpufreq bits.
Cheers,
/ magnus
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