I have two USB devices which present them selves with the exact same information.
root@nordlys:/$ dmesg
[27428.655362] usb 1-2: new full-speed USB device number 18 using xhci_hcd
[27428.678006] usb 1-2: New USB device found, idVendor=09d8, idProduct=0320
[27428.678013] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[27428.678017] usb 1-2: Product: RFID Device (COM)
[27428.678020] usb 1-2: Manufacturer: OEM
....
....
[27428.751580] usb 3-1.2: new full-speed USB device number 16 using ehci_hcd
[27428.850532] usb 3-1.2: New USB device found, idVendor=09d8, idProduct=0320
[27428.850539] usb 3-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[27428.850544] usb 3-1.2: Product: RFID Device (COM)
[27428.850547] usb 3-1.2: Manufacturer: OEM
I tried finding differences by comparing the two using root@nordlys:/$ lsusb -v
. Also here they are exactly the same.
I need the ability to know with certainty which of the two devices I am communicating with. So far the only things I can think of is to connect the devices in a certain sequence or connect the devices in specific USB ports on the computer. I find these two to be bad solutions and am wondering if any of you know other ways to distinguish USB devices?
A third solution which I find best so far is to communicate with the devices and try to find differences there that can uniquely identify them.
Added at a later time: I see that one device is USB2 while the other is USB3, meaning they use eHCI and xHCI. Is it possible to make UDEV see the difference and make persistent symlinks in /dev depending on this?
sudo blkid -sUUID
? Further references on the blkid manual page