imx8mq CPU Temperature

[bineyamtafesse]

I am running the following configuratoin
CPU: imx8mq (custom PCB)

Linux OS: Linux 4.9.123 

I noticed the TMU generated temperature exceeded warnings and cutoff on power up. The critical temperature limit of 95C was tripped (the processors were nowhere near this temperature). I modified the trip-temperature to 125C and the device boots through u-boot and kernel and functions as intended (and has been working for weeks).  Now, increasing the temperature is a temporary solution.  What is the expectation in terms of calibration? I see there is a definition in the u-boot under "tmu" that looks like a calibration table.  Is the expectation that we calibrate every unit?

[jming]

Hi @bineyamtafesse 

My IMX8M custom board has the similar issue, Have you fixed the issue or not ?

Thanks.

[weidong_sun]

Hello bineyam，

      For i.mx8MQ application, the better choice is to use a heatsink according to real application.

In addition, The limit temperature of die is 125 degrees Celsius.  So, you can't configure the temperature to exceed 125 degrees Celsius.  Probably 115 degrees Celsius can meet your requirement.

Have a nice day!

NXP TIC team

[bineyamtafesse]

Hi weidong.sun‌,

The issue is that on immediate power-on (from room temperature), the u-boot reads 112 Celsius. Clearly, the chip is not heating up to 112C  in less than 10 seconds while only pulling 2W.  This is why I'm asking if additional calibration is needed.