Messages in this thread | | | Subject | Re: [PATCH v2 02/10] cpufreq: provide data for frequency-invariant load-tracking support | From | Dietmar Eggemann <> | Date | Thu, 13 Jul 2017 14:08:13 +0100 |
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On 13/07/17 13:40, Sudeep Holla wrote: > > > On 11/07/17 16:21, Dietmar Eggemann wrote: >> On 11/07/17 07:39, Viresh Kumar wrote: >>> On 10-07-17, 14:46, Rafael J. Wysocki wrote:
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>> Like I said in the other email, since for (future) >> arm/arm64 fast-switch driver, the return value of >> cpufreq_driver->fast_switch() does not give us the information that the >> frequency value did actually change, we have to implement > > I was under the impression that we strictly don't care about that > information when I started exploring the fast_switch with the standard > firmware interface on ARM platforms(until if and when ARM provides an > instruction to achieve that). > > If f/w failed to change the frequency, will that be not corrected in the > next sample or instance. I would like to know the impact of absence of > such notifications.
In the meantime we agreed that we have to invoke frequency invariance from within the cpufreq driver.
For a fast-switch driver I would have to put the call to arch_set_freq_scale() somewhere where I know that the frequency has been set.
Without a notification (from the firmware) that the frequency has been set, I would have to call arch_set_freq_scale() somewhere in the driver::fast_switch() call assuming that the frequency has been actually set.
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