Messages in this thread | | | Date | Mon, 20 Feb 2017 15:26:08 +0530 | From | Viresh Kumar <> | Subject | Re: [RFC][PATCH] cpufreq: User/admin documentation update and consolidation |
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On 18-02-17, 02:36, Rafael J. Wysocki wrote: > +CPU Initialization > +================== > +
> +Next, the scaling driver's ``->init()`` callback is invoked with the policy > +pointer of the new CPU passed to it as the argument. If the policy object > +pointed to by it is new
The callbacks don't need to do anything special for a new policy. Infact, ->init() is only called for new policies or policies which don't have any active CPUs as of now.
> , that callback is expected to initialize the performance > +scaling hardware interface for the given CPU (or, more precisely, for the set of > +CPUs sharing the hardware interface it belongs to, represented by its policy > +object) and to set parameters of the policy, like the minimum and maximum > +frequencies supported by the hardware, the table of available frequencies (if > +the set of supported P-states is not a continuous range), and the mask of CPUs > +that belong to the same policy.
Maybe we should explicitly mention that both online and offline CPUs should be set in the mask ?
> That mask is then used by the core to populate > +the policy pointers for all of the CPUs in it. > + > +The next major initialization step for a new policy object is to attach a > +scaling governor to it (to begin with, that is the default scaling governor > +determined by the kernel configuration, but it may be changed later > +via ``sysfs``). First, a pointer to the new policy object is passed to the > +governor's ``->init()`` callback which is expected to initialize all of the > +data structures necessary to handle the given policy and, possibly, to add > +a governor ``sysfs`` interface to it. Next, the governor is started by > +invoking its ``->start()`` callback.
The rest of it looked good. Nice work Rafael :)
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
-- viresh
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