NanoPi R5C sporadic freezes

Troubleshooting
1

Creating a bug report/issue

I have searched the existing open and closed issues

Required Information

  • DietPi version | Ranging from 9.8.0 to 9.19.2
  • Distro version | Ranging from Bookworm to Trixie
  • Kernel version | Ranging from 6.6.56-current-rockchip64 to 6.12.57-current-rockchip64
  • Architecture | arm64
  • SBC model | NanoPi R5S/R5C (aarch64) = R5C 4GB RAM 32GB eMMC
  • Power supply used | Meanwell HDR-15-5 5V 2.4A
  • SD card used | Onboard eMMC

Additional Information (if applicable)

  • Software title | N/A
  • Was the software title installed freshly or updated/migrated? N/A
  • Can this issue be replicated on a fresh installation of DietPi? Yes, I created a Trixie system using the latest release in September this year and have the same problems.
  • Bug report ID | N/A

Steps to reproduce

  1. Install DietPi > v9.7.1 with kernel > 5.10.160 on a NanoPi R5C
  2. Wait for a sporadic freeze

Expected behaviour

  • System should stay online

Actual behaviour

  • System freezes
  • Attached touchscreen unresponsive
  • Network connection down
  • SYS led stops flashing
  • Need manually power cycling to bring back online
  • No indication to fault in logs or dmesg

Extra details

  • I have a series of NanoPi R5C PCs at remote locations for PLC monitoring. Ever since I started to upgrade systems past DietPi v9.7.1 I have had issues with the PCs randomly going offline. When I get to the PC the SYS light has stopped flashing, its not connected to the network, the touchscreen and connected device on LAN cannot communicate with the R5C and I have to power cycle to get the device back online.
  • I have tried to find the source of the problem with OTEL (running in a Docker container on the host + LOKI on a remote server but this has not produced anything useful yet around freeze times.
  • I use Telegraf to send metrics to a remote server including CPU, RAM, disk usage etc but that has only yielded momentarily (<5s) high (731M ops/sec) Context Switches occasionally but not before all freeze events. Baseline switching is at ~2K ops/sec
  • I use the same (UPS protected) power supply across all devices and before using newer (> v9.7.1) DietPi images I have not had any issues.
  • Coincidental findings are lower CPU usage with more recent DietPi versions, average CPU usage on older systems averages ~37%, my latest install runs at ~12% with identical workloads.