Comment # 15 on bug 976813 from Jean-Claude Dole

I have made the same tests on three different computer :

1�) A test on a test server running 13.2 ( no-name box  asus z97 motherboard )
I tested the scanner on one usb 2.0 motherboard connector, one usb 3.0
motherboard connector, one all_in_one 2"5 front interface on usb 3.0 connector.
All tests succeed and the used driver is xhci_hcd.

2�) A test on a laptop running 13.2 ( ASUS G75VW )
I tested the scanner on all usb 3.0 connector. All test failed
The driver in use is ehci-pci.
The NVIDIA sound controller is recognize also as a scanner on the same bus.

3�) A test on a test laptop running 13.1 and 13.2  ( HP Pavillion DV9500 series
)
I tested the scanner on one usb 2.0 connector. There is no usb 3.0 connectors.
All tests succeed and the used driver is ehci-pci.

I remark that on my laptop ( asus ) and on the hp laptop, this is the same
driver which is in use.
The only difference I can see is that the sound controler ( NVIDIA GF114 HDMI
Controller ) is on the same bus as the scanner, and respond to scanner discover
command.

Two different driver ( xhci_hcd, ehci-pci ) are convenient for the scanner.
It seems that the ehci-pci is used because of the NVIDIA sound controller.

My thought is because the NVIDIA sound controller is on the same bus as the
scanner and because it is detected as a scanner, this make the the scanner
faulty.