Jan 29 2011
I have a PC Engines alix2d3 single-board computer – a really nice compact system with an AMD Geode processor, 256MB RAM, compact flash storage and three 10/100MB network ports – acting as my traffic-shaper and network gateway. Since this machine is extremely reliable, always on, and has spare USB ports it seemed like a sensible place to plug in the USB cable from my new UPS. There have been several power-cuts recently (some due to external factors, and some due to a dodgy toaster!) and the time spent recovering filesystems from unexpected restarts was starting to become inconvenient…
The ALIX has two USB2.0 ports, and I first plugged the UPS into the lower port. Unfortunately, this led to messages similar to the following being output every second or so:
usb 2-1: new full speed USB device using ohci_hcd and address 47
usb 2-1: New USB device found, idVendor=051d, idProduct=0003
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 2-1: Product: Smart-UPS X 750 FW:COM 03.6 / UPS 03.6
usb 2-1: Manufacturer: American Power Conversion
usb 2-1: SerialNumber: xxxxxxxxxxxx
generic-usb 0003:051D:0003.010E: hiddev0,hidraw0: USB HID v1.00 Device [American Power Conversion Smart-UPS X 750 FW:COM 03.6 / UPS 03.6] on usb-0000:00:0f.4-1/input0
hub 2-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
usb 2-1: USB disconnect, address 47
I tried rebuilding the kernel, upgrading the kernel to 2.6.36, all to no avail. I then solved the problem by… plugging the UPS into the other USB port.
Who says the simplest fixes aren’t the best? 😉