An important default kernel behavior change worth noting in advance for the upcoming [1]Linux 7.1 kernel is that the system will attempt to power-off automatically if encountering any fatal ACPI errors. Up to now the Linux kernel has just logged ACPI fatal errors.

A change queued into the Linux power management subsystem's "linux-next" Git branch ahead of Linux 7.1 is altering the default system behavior if encountering a fatal ACPI error. With existing Linux kernels when hitting any ACPI fatal error, there would simply be a " Fatal opcode executed " message sent to the kernel system log. But for Linux 7.1+ the plan is to try powering off the system by default.

This change in behavior is for better match the intended ACPI specifications. The ACPI specification notes:

"This operation is used to inform the OS that there has been an OEM-defined fatal error.

...

In response, the OS must log the fatal event and perform a controlled OS shutdown in a timely fashion."

So technically it's Linux that has been out-of-spec with just logging an error to the log but letting the system continue on. Hopefully your system rarely or never encounters fatal ACPI errors, but there is always the chance of buggy system firmware.

But for those wanting to maintain the existing behavior of not powering off, [2]the patch making this change adds a new acpi.poweroff_on_fatal=0 option. Set that if you don't want your system to power off in the event of any ACPI fatal errors.



[1] https://www.phoronix.com/search/Linux+7.1

[2] https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=591230c6f268306a673112fc3c3b74ab06fa9ee3