Hi, > Gesendet: Donnerstag, 24. Juni 2021 um 15:29 Uhr > Von: "Eric Woudstra" <ericwouds@xxxxxxxxx> > The SOC runs unthrotlled slowly to 80 degrees. This takes minutes. Polling interval 1 second or less does not matter much when looking at these temperature rise times > > After that in more then an hour it slowly creeps up to 85. I believe the design is so that the SOC, under normal circumstances, can run at 1.35 GHz without throttling frequency, without heatsink. It just needs a safeguard for different circumstances. > > Most of these SOCs can also run in industrial grade circumstances, which means up to 85 degrees ambient temperature already . If not industrial then this would be 60 degrees ambient already > > But only someone at Mediatek can confirm this maybe Matthias knows anybody? get_maintainers-script shows no mtk employee for mtk_thermal driver, added Sean and Ryder as common Linux-Contacts... Daniel from openwrt have some other mt7622 Boards maybe he can test the Fan approach below > On Jun 24, 2021, 12:21 PM, at 12:21 PM, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > >Found that: > > > >https://download.kamami.pl/p579344-MT7622A_Datasheet_for_BananaPi_Only%281%29.pdf > > > >Chapter 3.3 - Thermal Characteristics > > > >Given the values I suggest: > > > > - Passive - 80°C > > > > - Hot - 90°C > > > > - Critical - 100°C maybe adding FAN (r64, don't know for other mt7622 boards) for lower 2 trips (with adjusted temperature points) and cpu-throtteling for upper 2 trips something like this (used the 70/80 trip points discussed before): --- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi @@ -134,6 +134,13 @@ }; }; + fan0: pwm-fan { + compatible = "pwm-fan"; + #cooling-cells = <2>; + pwms = <&pwm 2 10000 0>; + cooling-levels = <0 102 170 230>; + }; + thermal-zones { cpu_thermal: cpu-thermal { polling-delay-passive = <1000>; @@ -143,13 +150,13 @@ trips { cpu_passive: cpu-passive { - temperature = <47000>; + temperature = <70000>; hysteresis = <2000>; type = "passive"; }; cpu_active: cpu-active { - temperature = <67000>; + temperature = <80000>; hysteresis = <2000>; type = "active"; }; @@ -170,14 +177,12 @@ cooling-maps { map0 { trip = <&cpu_passive>; - cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>, - <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; + cooling-device = <&fan0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; }; map1 { trip = <&cpu_active>; - cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>, - <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; + cooling-device = <&fan0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>; }; map2 { @@ -428,6 +433,7 @@ pwm: pwm@11006000 { compatible = "mediatek,mt7622-pwm"; reg = <0 0x11006000 0 0x1000>; + #pwm-cells = <3>; interrupts = <GIC_SPI 77 IRQ_TYPE_LEVEL_LOW>; clocks = <&topckgen CLK_TOP_PWM_SEL>, <&pericfg CLK_PERI_PWM_PD>, regards Frank
