On Di, 2018-08-14 at 14:49 +0530, Muni Sekhar wrote: > /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 480M > > |__ Port 2: Dev 91, If 0, Class=Hub, Driver=hub/4p, 480M > > |__ Port 2: Dev 100, If 0, Class=Hub, Driver=hub/3p, 480M > > |__ Port 1: Dev 101, If 0, Class=Vendor Specific Class, > Driver=ftdi_sio, 12M > > |__ Port 2: Dev 102, If 0, Class=Vendor Specific Class, > Driver=ftdi_sio, 12M > > |__ Port 3: Dev 103, If 0, Class=Vendor Specific Class, > Driver=ftdi_sio, 12M In this case XHCI. But you need the failing case. Presumably also XHCI, but that is not guaranteed. In case lsusb -t fails in the failure case, attach another device into the port your serial devices fails at. Regards Oliver
