XU4 cpu speed configurability?

[ej0rge]

I decided to klipperize an old 3d printer and found some of my orange pi boards dead, so i ended up selecting my XU4 for the task. 

 

Fast forward 24 hours and i'm fighting MCU timeouts. Klipper doesn't know what happened just that the mcu stopped responding.  And their knowledge base article is basically "gosh it could be anything". 

 

One seat of the pants observation i made was that the XU4 idles along at 600mhz with a load average of about 0.1 and it seemed like the load average increased maybe before the mcu stopped responding. 

 

The MCU in question is an SKR Pico, aka rp2040 with a usb connection. The mcu is not receiving power from the xu4 (there's a jumper) - I've tried both usb3 and usb2 ports on the XU4 with no difference. 

 

I recall that many years ago i resolved a similar issue with an H2+ based board and Octoprint by switching the cpufreq governor to "performance" which of course just pegs it at the top speed. 

 

But on that board, armbian-config lets me select what that maximum speed is, so as to avoid overheating. 

 

My XU4 is equipped with the flat little fan. I do have some large heatsinks and thermal adhesive. I'm a little worried that it might run too hot if it's at 1.4ghz all the time. 

 

sysfs tells me there are a ton of scaling frequencies available, but it appears that i can't just, select one. 

 

Any hints? 

[ej0rge]

Well, two things. 

 

1: The cpu clock changing on the fly was not the issue. That may just be an old issue with H3 series SOCs. 

 

2: The XU4 likes running at 1.4ghz continually just fine. fwiw I'm using a newish 5v 4a power supply. It doesn't even get warm or spin up the fan while printing.