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. -- viresh
