Back in Linux < 3.6 days, the cdc-wdm ports exposed by the QMI driver were flagged as owned by the 'usb' subsystem. That changed in 3.6 when the subsystem was renamed to 'usbmisc': https://mail.gnome.org/archives/networkmanager-list/2012-June/msg00125.html So, rename the port subsystem type enumn to 'usbmisc'.