iMX8MM Changes in trip points are not updated in sysfs

[hfranco]

Hi all!

I'm trying to change the trip points of the iMX8MM device tree:

	thermal-zones {
		cpu-thermal {
			polling-delay-passive = <250>;
			polling-delay = <2000>;
			thermal-sensors = <&tmu>;
			trips {
				cpu_alert0: trip0 {
					temperature = <85000>;
					hysteresis = <2000>;
					type = "passive";
				};

				cpu_crit0: trip1 {
					temperature = <95000>;
					hysteresis = <2000>;
					type = "critical";
				};
			};

			cooling-maps {
				map0 {
					trip = <&cpu_alert0>;
					cooling-device =
						<&A53_0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
						<&A53_1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
						<&A53_2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
						<&A53_3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
				};
			};
		};
	};

 
I'm trying to update the values from 85C to 95C and from 95C to 105C. However, when I compile the device tree and check the /sys/class/thermal/thermal_zone0/trip_point_0_temp, the values are the default ones: 85C and 95C.

Tested on NXP kernel 5.4 and 5.15. Does anyone know what's happening? Is this a bug or I should configure the device tree in a different way?

Tested on iMX8MM DL and iMX8MP.

Thanks!

[Zhiming_Liu]

Hi

 You need change source code based on a yocto patch or using devtool modify linux-imx

Here is my test result based on devtool:

root@imx8mp-lpddr4-evk:~# cat /sys/class/thermal/thermal_zone0/trip_point_0_temp
95000
root@imx8mp-lpddr4-evk:~# cat /sys/class/thermal/thermal_zone0/trip_point_1_temp
105000

[hfranco]

Hi @Zhiming_Liu, thanks for the reply.

As far as I understand, for iMX8M, the code that I should look at is imx8mm_thermal.c, the imx_thermal.c is not being used in this case. Am I correct?

Best Regards,
Hiago.

[Zhiming_Liu]

Hi @hfranco 

Correct, let me test and give you answer about this issue.