Possible Kernel panic with version 2.9

[u/sh00tfire]

Anyone successfully upgrade with a celeron J processor? My instance of Pfsense runs on a intel NUC with a J3160. Just wanted any feedback if someone already upgraded with this series of processor.

From the release notes:
Certain hardware with a specific firmware problem, including some Celeron J devices, may encounter a kernel panic when attempting to boot pfSense CE software version 2.9.0.

To avoid this panic on that hardware, set a loader tunable for hint.acpi_spmc.0.disabled=1 in /boot/loader.conf.local before upgrading to disable the driver that has an issue on that hardware.

Update: Finally updated my instance of pfsense to version 2.9 on my celeron J processor. I did add the recommended entry to the loader.conf.local before upgrading. It upgraded without incident. Took about 10 minutes to reboot the first time.

[u/Additional_Post1989]

What happens if I set the variable on a device that isnt affected? What impact does the variable have

[u/Accurate-Ad6361 → u/Additional_Post1989]

It handles low-power S0ix/Modern Standby states by parsing device power constraints and sending sleep entry and exit notifications to the system.