ACPI Storm / kworker thread hogging first core

vem_rw

Processor: N4200

I have found that there is a kworker thread continually running on the first core, taking somewhere between 80% and 95% of that core.

Investigating this further I found that /sys/firmware/acpi/interrupts/gpe03 was being triggered roughly 5000 times per second.

I am able to mask this interrupt, which releases the kworker thread.

I don't know what generates GPE03, so I don't know if this could now be masking a genuine fault.

vem_rw

Tracked this down to a SimCom modem:

• Removed modem (and interrupt mask) and issue not present
• Replace with Sierra Wireless modem and issue not present
• Replace with another SimCom modem (same model) and issue returned

Any thoughts on what the root cause may be?