On 25-04-22, 17:34, Rex-BC Chen wrote: > We found that the pulses of cpu voltage could be observed when > frequency is fixed (scaling_max_freq == scaling_min_freq) if using > cpufreq_generic_get as '.get' callback in MT8186. > cpufreq framework will constantly (~ 1 sec) call 'update' if the policy Which function gets called here in that case ? I would expect cpufreq_driver_target() to not make a call to MTK driver in that case, after it finds that new and old frequency are same (it will check the corresponding freq from cpufreq table). > frequency is NOT equal to hardware frequency in > cpufreq_verify_current_freq. > The problem is that there might be a tiny difference between the policy > frequency and the hardware frequency even they are very close. > e.g. policy frequency is 500,000,000 Hz however, hardware frequency is > 499,999,726 Hz for MT8186 opp15. > > To prevent the voltage pulses, we currently use the software cached > values as you pointed out. > I wonder is it possible to add a tolerence for checking difference > between policy frequency and hardware frequency in cpufreq framework so > that we can use cpufreq_generic_get as callback without pulse issue. > Or any suggestion would be appreciated. -- viresh
