On 19/06/2021 14:19, ericwouds@xxxxxxxxx wrote: > From: Eric Woudstra <ericwouds@xxxxxxxxx> > > Cpu-thermal is set to use all frequencies already at 47 degrees. > Using the CPU at 50 for a minute, the CPU has reached 48 degrees, is > throttled back to lowest setting, making the mt7622 terrribly slow. > Even at this low speed, the CPU does not cool down lower then 47 so > the CPU is stuck at lowest possible frequency until it shut down and > stays off for 15 minutes. > > cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>, > <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; > > This should not be set al every cooling map. It should only be set at > the highest cooling map. Same as in the example: > > https://www.kernel.org/doc/Documentation/devicetree/bindings/ > thermal/thermal.txt line 272 > > But then without the fan and added a third map. > > Now temperature will be regulated at 87 degrees celcius. At temperatures > lower then 87, all frequencies can be used. 47°C is really a too low temperature and this performance drop is normal. I would not remove the passive mitigation but try by increasing the CPU temp to 70°C and by changing the active trip point to 80°C. If it works fine, try 75°C and 85°C. To test, the thermal killer is dhrystone (one thread per cpu). With a 75°C passive trip point, the step wise thermal governor, I think the mitigation will happen smoothly providing better performances, and probably the fan won't fire. > Also see the post: > > http://forum.banana-pi.org/t/bpi-r64-only-10-cpu-speed-at-already-48- > degrees-celcius-speed-not-increasing-anymore/12262 > > Signed-off-by: Eric Woudstra <ericwouds@xxxxxxxxx> > --- > arch/arm64/boot/dts/mediatek/mt7622.dtsi | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/boot/dts/mediatek/mt7622.dtsi b/arch/arm64/boot/dts/mediatek/mt7622.dtsi > index 890a942ec..b779c7aa6 100644 > --- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi > +++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi > @@ -170,14 +170,14 @@ cpu-crit { > cooling-maps { > map0 { > trip = <&cpu_passive>; > - cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>, > - <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; > + cooling-device = <&cpu0 0 0>, > + <&cpu1 0 0>; > }; > > map1 { > trip = <&cpu_active>; > - cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>, > - <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; > + cooling-device = <&cpu0 0 0>, > + <&cpu1 0 0>; > }; > > map2 { > -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
