THANK YOU for the suggestion to use tlp to change the USB autosuspend power settings. I moved an Arch installation to a new computer and was suffering from maddening USB keyboard disconnects. I could type for max 10 seconds after plugging in the keyboard before it would go dead again. I must have unplugged-replugged over a hundred times while troubleshooting the problem.
Simply installing the tlp utility and running the command sudo tlp usb resolved the problem.
Glad you got it sorted.
This thread is quite old and now there is a fix, I'll close it: https://wiki.archlinux.org/index.php/Fo … Bumping.27