I am working on an Ubuntu Core project that needs serial-port paths for a single USB FTDI device that exposes two interfaces. There needs to be two exposed paths, one for each of the device’s two interfaces.
It has been suggested that snapd may need to support a third (as-yet-identified) attribute since the vendorID and the productID are the same for the two interfaces/paths. Perhaps snapd already creates two paths in such a case, differentiated by the trailing digit? (Customer has the USB device now, so I cannot test, but they are looking for clear understanding to determine whether they need to file a snapd feature request bug.)
Suppose this slot for a two-interface device:
slots: serial-port: path: /dev/serial-port-BE0 usb-vendor: 0xTHEVENDOR usb-product: 0xTHEPRODUCT
Would snapd deterministically provide these paths?
- device’s first interface: /dev/serial-port-BE0
- device’s second interface: /dev/serial-port-BE1
Or, is this required (with a snapd enhancement for the third attribute, of course):
slots: serial-port: path: /dev/serial-port-BE0 usb-vendor: 0xTHEVENDOR usb-product: 0xTHEPRODUCT THIRD-ATTRIBUTE: X serial-port: path: /dev/serial-port-BE1 usb-vendor: 0xTHEVENDOR usb-product: 0xTHEPRODUCT THIRD-ATTRIBUTRE: Y