Suspecting the issue is related to the EHCI i have plugged a PCMCIA EHCI module on my laptop expansion slot. This module is certified to be fully USB2 compliant, it uses a VIA chip memory mapped to the PCI bus (no PCI_IO, it is PCI_MEM_ONLY).
I have compiled the right kernel module, installed it, and the ICE100B has been perfectly recognized on the USB bus
> lsusb | grep "Analog Devices"
Bus 001 Device 015: ID 064b:0225 Analog Devices, Inc. (White Mountain DSP)
so i invoked UrJtag
jtag> cable ice-100b
ICE-100B firmware version is 2.0.8
This time i had success, the cable has been recognized and it is working!
My conclusion is: the problem was related to the hw of the USB driver, the ICE-100B needs a FULLY USB2 compliant hw, everything that is USB1 will not work.