30.12.2020 07:46, Viresh Kumar пишет: > On 28-12-20, 17:03, Dmitry Osipenko wrote: >> 28.12.2020 09:22, Viresh Kumar пишет: >>> On 24-12-20, 16:00, Dmitry Osipenko wrote: >>>> In a device driver I want to set PD to the lowest performance state by >>>> removing the performance vote when dev_pm_opp_set_rate(dev, 0) is >>>> invoked by the driver. >>>> >>>> The OPP core already does this, but if OPP levels don't start from 0 in >>>> a device-tree for PD, then it currently doesn't work since there is a >>>> need to get a rounded-up performance state because >>>> dev_pm_opp_set_voltage() takes OPP entry for the argument (patches 9 and >>>> 28). >>>> >>>> The PD powering off and performance-changes are separate from each other >>>> in the GENPD core. The GENPD core automatically turns off domain when >>>> all devices within the domain are suspended by system-suspend or RPM. >>>> >>>> The performance state of a power domain is controlled solely by a device >>>> driver. GENPD core only aggregates the performance requests, it doesn't >>>> change the performance state of a domain by itself when device is >>>> suspended or resumed, IIUC this is intentional. And I want to put domain >>>> into lowest performance state when device is suspended. >>> >>> Right, so if you really want to just drop the performance vote, then with a >>> value of 0 for the performance state the call will reach to your genpd's >>> callback ->set_performance_state(). Just as dev_pm_opp_set_rate() accepts the >>> frequency to be 0, I would expect dev_pm_opp_set_rate() to accept opp argument >>> as NULL and in that case set voltage to 0 and do regulator_disable() as well. >>> Won't that work better than going for the lowest voltage ? >>> >> >> We can make dev_pm_opp_set_voltage() to accept OPP=NULL in order to >> disable the regulator, like it's done for dev_pm_opp_set_rate(dev, 0). >> Although, I don't need this kind of behaviour for the Tegra PD driver, >> and thus, would prefer to leave this for somebody else to implement in >> the future, once it will be really needed. >> >> Still we need the dev_pm_opp_find_level_ceil() because level=0 means >> that we want to set PD to the lowest (minimal) performance state, i.e. >> it doesn't necessarily mean that we want to set the voltage to 0 and >> disable the PD entirely. GENPD has a separate controls for on/off. > > Ok. > I'll separate the OPP patches from this series and will prepare v3, thank you for the review!
