Re: [PATCH V2] cpufreq: Make sure CPU is running on a freq from freq-table

[Viresh Kumar]

On 28 November 2013 18:39, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> acpi-cpufreq is one at least.
>
> Anyway, this isn't about ACPI or anything like that, but hardware.  Generally
> speaking, on modern Intel hardware the processor itself chooses the frequency
> to run at and it may do that behind your back.  Moreover, it can choose a
> frequency different from the one you asked for.  And it won't choose one that
> it can't run at for that matter. :-)
>
> Overall, I don't believe that the problem you're trying to address is relevant
> for any non-exotic x86 hardware.

Okay.. So wouldn't it be better that we add this special flag only when we
face a real problem? Otherwise this flag might stay unused for long time
and then we might end up removing it..

>> > So there should be a flag for
>> > drivers indicating whether or not frequencies (or operation points in
>> > general) are directly testable and the check should only be done for
>> > the drivers with the flag set.
>>
>> Probably a flag with properties exactly opposite to what you mentioned,
>> so that we don't need to modify most of the drivers..
>
> That would work too if you prefer it.

In case we need this flag, what should we name it?
ALLOW_UNKNOWN_FREQ ??
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