We're using the i.MX8M (Quad) in a product connected to a 1080p LVDS display. We use Yocto as build system and a QT WebEngine based browser running in kiosk mode under Weston.
When we bring up a webpage in the browser and start scrolling the page (doesn't matter how simple the page is) after a short time (less than a minute) the GPU is overheated and the kernel reports:
[ 930.557040] hantro receive hot notification event: 1
[ 930.562170] System is too hot. GPU3D will work at 1/64 clock
We have a passive heat-sink attached to the CPU and no real CPU/GPU load except for the browser. With no user interaction the CPU temperature is ~70 C degrees and under interactions it goes up to around ~84 C before the GPU clock is decreased to 1/64.
Even if the browser is not running the CPU is idling on ~70 C degrees.
We have experienced the same problem with both a 4.9 kernel (Yocto Morty based build) and a newer 4.14 (Yocto Sumo based).
Has anyone else successfully used i.MX8M in a similar setup using passive cooling?
What can be done to lower the heat/power consumption?