System freeze with 5.16-rc

At the moment I’am experiencing system freezes with 5.16-rc3 and 5.16-rc4. Older kernels including 5.14, 5.15 and even 5.15-rt work without freezes for long time (weeks without reboot) while 5.16 freezes after minutes.

Freeze seems to be complete and no life signs could be observed, caps lock doesn’t toggle the corresponding led.

So what is the current way of debugging this? Can I do something without external serial interface capturing kernel log?

Did you try some of the methods listed here: