Debug mouse freezing on Ubuntu

Question

I have been using Ubuntu 12.04 LTS on my work desktop for a few months. Yesterday, I started having issues with my USB mouse.

Whenever I type for a while, and I try to move the mouse afterwards, it takes a couple of seconds to respond.

I kept a tail of the system log open on a side screen, and also the graphical process monitor. I have not noticed any unusual activity during the mouse freezes.

What I did notice one was that the mouse tracking light had gone into an odd pulsing mode while it was frozen once. It looked like a power-save mode.

What other log views or debug tools could I use to determine what's happening?

Solution

It turns out this was caused by powernap. Since it's a desktop PC, I thought it would be fine to remove it:

sudo apt-get remove powernap

I've had no side effects. However, some people may want to keep PowerNap. According to this answer, you could also just disable the USB suspend: https://askubuntu.com/questions/80638/how-to-disable-auto-power-off-of-usb-devices-like-usb-mouse

sudo powernap-action --disable usb_autosuspend