On 13/07/17 14:08, Dietmar Eggemann wrote: > 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: > > [...] > >>> 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. >
Yes, that's what I was thinking too. -- Regards, Sudeep
