Aw: Re: Re: Re: [PATCH] Fix mt7622.dtsi thermal cpu

From: Frank Wunderlich
Date: Fri Jun 25 2021 - 08:29:26 EST


> Gesendet: Freitag, 25. Juni 2021 um 13:47 Uhr
> Von: "Daniel Lezcano" <daniel.lezcano@xxxxxxxxxx>

> > but we need to disable the passive trip as cpu-trotteling starts there...the higher temperature trips are currently not reached
>
> Sorry, can you rephrase it ? I'm not getting the point.

the problem currently is that passive is at 47degress Celsius and trottles cpu, active (67°C) and hot points are never reached this way. so at least we need to change temperatures in dtsi, and maybe disable cpu-trotteling on passive trip. imho fan will never start if it is in active and cpu is trottled before in passive

> > summary
> >
> > moving fan and cpu_thermal-override to bananapi-r64.dts
> >
> > passive-trip: cooling-device = <&cpu0/1 0 0> as in erics Patch
> > active trip: cooling-device = <&fan0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> > the other 2 unchanged
> >
> > but i suggest changing the temperature points in mt7622 dtsi as this is SoC specific
> >
> > so basicly:
> >
> > --- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > @@ -143,13 +143,13 @@ cpu_thermal: cpu-thermal {
> >
> > trips {
> > cpu_passive: cpu-passive {
> > - temperature = <47000>;
> > + temperature = <70000>;
>
> May be increase the passive temp to 75°C.
>
> > hysteresis = <2000>;
> > type = "passive";
> > };
> >
> > cpu_active: cpu-active {
> > - temperature = <67000>;
> > + temperature = <80000>;
> > hysteresis = <2000>;
> > type = "active";
> > };
>
> Move the active trip 'cpu_active' to mt7622-bananapi-bpi-r64.dts. and
> set it to 70°C in the mt7622-bananapi-bpi-r64.dts, so the fan will act
> before the cpu throttling.
>
> The behavior should be the following: The temperature reaches 70°C, the
> fan will start, if the temperature continues to increase, it will
> increase the speed. If the temperature reaches 75°C, the fan is still
> rotating at full speed but the cpu begins to be throttled.

passive to 75 and active lower to 70? is this as intended that active comes before passive?

mt7622-bananapi-bpi-r64.dts:

&cpu_thermal {
trips {
cpu_passive: cpu-passive {
temperature = <75000>;
hysteresis = <2000>;
type = "passive";
};

cpu_active: cpu-active {
temperature = <70000>;
hysteresis = <2000>;
type = "active";
};
};

cooling-maps {
map1 {
trip = <&cpu_active>;
cooling-device = <&fan0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
};
};
};


> AFAIU, it is a Cortex-A53 running @1.35GH, so except the board is in a
> black metal box under the sun, I don't see how we can reach this thermal
> limits.
>
> > @@ -170,8 +170,8 @@ 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>;
>
> You should keep it untouched.

then cpu is trottled at passive point (currently 47°C) and imho fan does not start at active

> > };