Disable ehci_hcd in Linux

Background:

If your USB device cannot work with USB2.0, you need to disable ehci_hcd on Linux to make it work. If the ehci_hcd module is compiled into kernel, there is a way to disable it.

# cd /sys/bus/pci/drivers/ehci_hcd
# ls

You will see some files with 0000:00:xx.x format. Execute the command below to disable the files.
# sudo sh -c 'echo -n "0000:00:xx.x" > unbind'

The command should disable ehci_hcd. You have to do this every time Linux boots up. If you want to disable ehci_hcd automatically, put the below in your startup_script.

# cd /sys/bus/pci/drivers/ehci_hcd/
# sudo sh -c 'find ./ -name "0000:00:*" -print| sed "s/\.\///">unbind'