Re: [PATCH 1/2] cpufreq: Return error if ->get() failed in cpufreq_update_policy()

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Tuesday, February 25, 2014 11:38:14 AM Viresh Kumar wrote:
> On 25 February 2014 11:23, Srivatsa S. Bhat
> <srivatsa.bhat@linux.vnet.ibm.com> wrote:
> > Hmm, that's a good point. However, lets first think about the simple scenario
> > that the driver _is_ able to detect the current frequency from the hardware
> > (a non-zero, sane value) say X KHz, and that frequency is different from what
> > the cpufreq subsystem thinks it is (Y KHz).
> >
> > In the current code, when we observe this, we send out a notification and try
> > to adjust to X KHz. Instead, what I'm suggesting is to invoke the driver to
> > set the frequency to Y KHz, since that's what the cpufreq subsystems wants the
> > frequency to be at.
> 
> Actually we don't know at this point what cpufreq wants :)
> Governor will decide what frequency to run CPU at and lets leave it to
> that point.
> As the transition that we might end up doing here would be simply overridden
> very soon. And to be honest this decision must be taken by governor and not
> core. We just want to make sure core is in sync with hardware.

Well, why exactly does the core need to operate "current frequency" at all?

Rafael