On 25/04/2022 12:20, Rex-BC Chen wrote: >> However I am not sure if you solved your problem... see below: >> >>> For example: >>> mediatek cci set 1.2V originally. When cpufreq want to adjust lower >>> frequency adn set voltage to 1.0V. >>> The framework will remain using 1.2V to prevent crash of mediatek >>> cci. >> >> No, regulator_set_voltage() for proc_reg says: >> "NOTE: If the regulator is shared between several devices then the >> lowest >> request voltage that meets the system constraints will be used." >> >> Not the highest. So when your devfreq and cpufreq boots, calling >> regulator_set_voltage will still cause high frequency and low >> voltage. >> > > From the driver comment, I think it still needs to match "meets the > system constraints". > > From drivers, we can trace the driver and it finally to > regulator_get_optimal_voltage(). > In [1], the framework will get max voltage while finding each device's > voltage. > > [1]: > https://elixir.bootlin.com/linux/latest/source/drivers/regulator/core.c#L3815 Right, actually in your case it's the regulator_check_consumers() above that line, because you I think it's quite generic problem, so would be worth solving for more regulator consumers, but your approach is fine. At least I do not have anything smarter, at the moment. Best regards, Krzysztof
