dmesg shows the following:
[ 1328.912088] ipheth 2-3:4.2: Apple iPhone USB Ethernet device attached
[ 1329.426686] usb 2-3: USB disconnect, device number 125
[ 1329.438114] ipheth 2-3:4.2: Apple iPhone USB Ethernet now disconnected
[ 1336.433087] usb 2-3: new high-speed USB device number 9 using xhci_hcd
[ 1347.984080] usb 2-3: new high-speed USB device number 22 using xhci_hcd
[ 1358.584169] usb 2-3: new high-speed USB device number 29 using xhci_hcd
[ 1366.945110] usb 2-3: new high-speed USB device number 33 using xhci_hcd
[ 1367.098256] usb 2-3: Device not responding to setup address.
[ 1367.299318] usb 2-3: Device not responding to setup address.
[ 1367.500153] usb 2-3: device not accepting address 33, error -71
[ 1369.477103] usb 2-3: new high-speed USB device number 37 using xhci_hcd
[ 1369.630263] usb 2-3: Device not responding to setup address.
[ 1369.831241] usb 2-3: Device not responding to setup address.
[ 1370.032132] usb 2-3: device not accepting address 37, error -71
[ 1371.759107] usb 2-3: new high-speed USB device number 40 using xhci_hcd
[ 1371.912226] usb 2-3: Device not responding to setup address.
[ 1372.113199] usb 2-3: Device not responding to setup address.
[ 1372.314127] usb 2-3: device not accepting address 40, error -71
[ 1372.958091] usb 2-3: new high-speed USB device number 42 using xhci_hcd