On 15-06-21, 12:03, Daniel Lezcano wrote: > > [Cc Viresh] > > On 29/05/2021 19:09, Dmitry Osipenko wrote: > > All NVIDIA Tegra30 SoCs have a two-channel on-chip sensor unit which > > monitors temperature and voltage of the SoC. Sensors control CPU frequency > > throttling, which is activated by hardware once preprogrammed temperature > > level is breached, they also send signal to Power Management controller to > > perform emergency shutdown on a critical overheat of the SoC die. Add > > driver for the Tegra30 TSENSOR module, exposing it as a thermal sensor > > and a cooling device. > > IMO it does not make sense to expose the hardware throttling mechanism > as a cooling device because it is not usable anywhere from the thermal > framework. > > Moreover, that will collide with the thermal / cpufreq framework > mitigation (hardware sets the frequency but the software thinks the freq > is different), right ? I am not even sure what the cooling device is doing here: tegra_tsensor_set_cur_state() is not implemented and it says hardware changed it by itself. What is the benefit you are getting out of the cooling device here ? > The hardware limiter should let know the cpufreq framework about the > frequency change. > > https://lkml.org/lkml/2021/6/8/1792 > > May be post the sensor without the hw limiter for now and address that > in a separate series ? -- viresh
