Okay, for some reason, some of my USB webcams can only be used once, and then it must be unplugged and plugged in again before working. This obviously sucks big time. A quick way to fix this, is to unload and then load the usb 2.0 kernel module. To do this, start a terminal and use this command for USB 2.0:
sudo modprobe -vr ehci_hcd sudo modprobe -v ehci_hcd
and this command for USB 1.1:
sudo modprobe -vr uhci_hcd sudo modprobe -v uhci_hcd
After running those commands, your USB webcam should work again.
Written by Jannich Brendle lør 24 december 2011 In How to