RE: [EXT] Re: [PATCH v6] arm64: dts: ls1088a: add one more thermal zone node

[Andy Tang]

> -----Original Message-----
> From: Shawn Guo <shawnguo@xxxxxxxxxx>
> Sent: 2019年5月10日 11:14
> To: Andy Tang <andy.tang@xxxxxxx>
> Cc: Leo Li <leoyang.li@xxxxxxx>; robh+dt@xxxxxxxxxx;
> mark.rutland@xxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linux-pm@xxxxxxxxxxxxxxx; daniel.lezcano@xxxxxxxxxx; rui.zhang@xxxxxxxxx;
> edubezval@xxxxxxxxx
> Subject: [EXT] Re: [PATCH v6] arm64: dts: ls1088a: add one more thermal
> zone node
> 
> Caution: EXT Email
> 
> On Tue, Apr 23, 2019 at 10:25:07AM +0800, Yuantian Tang wrote:
> > Ls1088a has 2 thermal sensors, core cluster and SoC platform. Core
> > cluster sensor is used to monitor the temperature of core and SoC
> > platform is for platform. The current dts only support the first sensor.
> > This patch adds the second sensor node to dts to enable it.
> >
> > Signed-off-by: Yuantian Tang <andy.tang@xxxxxxx>
> > ---
> > v6:
> >         - add cooling device map to cpu0-7 in platform node.
I like to explain a little. I think it makes sense that multiple thermal zone map to same cooling device. 
In this way, no matter which thermal zone raises a temp alarm, it can call cooling device to chill out.
I also asked cpufreq maintainer about the cooling map issue, he think it would be fine.
I have tested and no issue found. 

Daniel, what's your thought?

Thanks,
Andy
> 
> @Daniel, are you fine with this version?
> 
> Shawn
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>
> On 22-04-19, 07:09, Andy Tang wrote:
> > Hi Viresh,
> >
> > Sorry to bother you. I have a question, hope I can get you help.
> > Here it is:
> >
> > I want to add multiple "Thermal Zone" support in dts ( driver is ready).
> > The final dts looks like below:
> >
> >         thermal-zones {
> >                 cpu_thermal: cpu-thermal {
> >                         polling-delay-passive = <1000>;
> >                         polling-delay = <5000>;
> >                         thermal-sensors = <&tmu 0>;
> >
> >                         trips {
> >                                 ccu_alert: ccu-alert {
> >                                         temperature = <85000>;
> >                                         hysteresis = <2000>;
> >                                         type = "passive";
> >                                 };
> >                                 ccu_crit: ccu-crit {
> >                                         temperature = <95000>;
> >                                         hysteresis = <2000>;
> >                                         type = "critical";
> >                         cooling-maps {
> >                                 map0 {
> >                                         trip = <&ccu_alert>;
> >                                         cooling-device =
> >                                                 <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> >                                 };
> >                         };
> >                 };
> >                 platform {
> >                         polling-delay-passive = <1000>;
> >                         polling-delay = <5000>;
> >                         thermal-sensors = <&tmu 1>;
> >                         trips {
> >                                 plt_alert: plt-alert {
> >                                         temperature = <85000>;
> >                                         hysteresis = <2000>;
> >                                         type = "passive";
> >                         };
> >                                 plt_crit: plt-crit {
> >                                         temperature = <95000>;
> >                                         hysteresis = <2000>;
> >                                         type = "critical";
> >                                 };
> >                         };
> >                         cooling-maps {
> >                                 map0 {
> >                                         trip = <&plt_alert>;
> >                                         cooling-device =
> >                                                 <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> >                                                 <&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> >                         }
> > }
> >
> > Here we have 2 thermal zones, but both map cpu0-7 as cooling device.  I have tested and didn't find any issues.
> > My query is: is it allowed to map same device as "cooling device" to more than one "thermal zone"?
>
> That should be fine IMO.
>
> --
> viresh
>
> --- End Message ---