The "Connect to device" dialog should allow manual USB VID/PID and bus.address specification, i.e. a "conn" spec for a specific driver's scan() run.
This might also help with the following issue originally reported in bug #1386: - No devices attached. - Start PV. - Attach an FX2 LA. - Click on "Connect to device", select fx2lafw, leave the "interface" on "USB" (default), click "Scan for devices using driver above". The expected result should be that the driver scans, finds the FX2 device, uploads firmware etc., but that doesn't happen. In the logs: sr: [00:25.905642] hwdriver: sr_config_list(): key 2147418112 (NULL) sdi (nil) cg NULL -> [uint32 20000] sr: [00:25.905739] usb: Neither VID:PID nor bus.address was specified. sr: [00:25.905770] hwdriver: Scan found 0 devices (fx2lafw). This is not OS-specific, happens on Windows and Linux.