Kyle - excellent find, I have confirmed that this was the cause of my issue, too. Thank you!
I had taken a quick glance at /etc/apcupsd/apcupsd.conf when I was failing to see communication working with my UPS, as I saw the expected lines to configure apcupsd for USB mode I had assumed there was a deeper problem and never got around to looking at it again. To confirm, the config contains these lines by default: UPSTYPE usb DEVICE /dev/ttyS0 I commented out the 'DEVICE' line like so: UPSTYPE usb #DEVICE /dev/ttyS0 Then I restarted the service with: # sudo systemctl restart apcupsd I no longer see the IRQ messages in dmesg output. Great! Does this apply to everyone else that has encountered this, I wonder? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1781016 Title: Slow flood of do_IRQ: No irq for vector To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1781016/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
