On Mon, Aug 3, 2020 at 3:26 PM Ionela Voinescu <ionela.voine...@arm.com> wrote: > > Hi guys, > > On Thursday 30 Jul 2020 at 09:11:28 (+0530), Viresh Kumar wrote: > > On 27-07-20, 15:48, Rafael J. Wysocki wrote: > > > On Wed, Jul 22, 2020 at 11:38 AM Ionela Voinescu > > > <ionela.voine...@arm.com> wrote: > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > > > index 036f4cc42ede..bac4101546db 100644 > > > > --- a/drivers/cpufreq/cpufreq.c > > > > +++ b/drivers/cpufreq/cpufreq.c > > > > @@ -2058,9 +2058,16 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier); > > > > unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, > > > > unsigned int target_freq) > > > > { > > > > + unsigned int freq; > > > > + > > > > target_freq = clamp_val(target_freq, policy->min, policy->max); > > > > + freq = cpufreq_driver->fast_switch(policy, target_freq); > > > > + > > > > + if (freq) > > > > + arch_set_freq_scale(policy->related_cpus, freq, > > > > + policy->cpuinfo.max_freq); > > > > > > Why can't arch_set_freq_scale() handle freq == 0? > > > > Sorry, I seem to have missed this question the first time around. > > arch_set_freq_scale() could handle freq == 0, but given that freq == 0 > is signaling an error here, I do believe this check is well placed, to > prevent a useless call to arch_set_freq_scale(). Also [1]:
So let me rephrase: Doesn't this check add overhead in the empty arch_set_freq_scale() case?