Ergänzung:
dmesg | grep usb ergibt folgendes:
[0.269329] usbcore: registered new interface driver usbfs
[0.269377] usbcore: registered new interface driver hub
[0.269507] usbcore: registered new device driver usb
[1.464124] usb 1-1: new high speed USB device number 2 using ehci\_hcd
[1.720084] usb 1-2: new high speed USB device number 3 using ehci\_hcd
[1.862570] scsi7 : usb-storage 1-2:1.0
[1.863415] usbcore: registered new interface driver usb-storage
[2.076132] usb 1-8: new high speed USB device number 5 using ehci\_hcd
[2.496131] usb 5-1: new full speed USB device number 2 using uhci\_hcd
[6.474158] usbcore: registered new interface driver btusb
[7.185693] input: CNF7129 as /devices/pci0000:00/0000:00:1d.7/usb1/1-8/1-8:1.0/input/input6
[7.185948] usbcore: registered new interface driver uvcvideo
[7.574797] usbcore: registered new interface driver usbserial
[7.575012] usbcore: registered new interface driver usbserial\_generic
[7.575021] usbserial: USB Serial Driver core
[7.803376] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[7.804005] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[7.804628] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2
[7.805105] usbcore: registered new interface driver option
[1317.164090] usb 3-2: new full speed USB device number 2 using uhci\_hcd
[1317.288084] usb 3-2: device descriptor read/64, error -71
[1317.512114] usb 3-2: device descriptor read/64, error -71
[1317.728139] usb 3-2: new full speed USB device number 3 using uhci\_hcd
[1317.852125] usb 3-2: device descriptor read/64, error -71
[1318.076109] usb 3-2: device descriptor read/64, error -71
[1318.292171] usb 3-2: new full speed USB device number 4 using uhci\_hcd
[1318.700089] usb 3-2: device not accepting address 4, error -71
[1318.812091] usb 3-2: new full speed USB device number 5 using uhci\_hcd
[1319.220109] usb 3-2: device not accepting address 5, error -71
[1823.100117] usb 1-2: USB disconnect, device number 3
[3682.676593] usb 1-2: new high speed USB device number 7 using ehci\_hcd
[3682.810899] scsi8 : usb-storage 1-2:1.0
[3683.264205] usb 3-2: new full speed USB device number 6 using uhci\_hcd
[3683.384157] usb 3-2: device descriptor read/64, error -71
[3683.608077] usb 3-2: device descriptor read/64, error -71
[3683.824119] usb 3-2: new full speed USB device number 7 using uhci\_hcd
[3683.948079] usb 3-2: device descriptor read/64, error -71
[3684.172150] usb 3-2: device descriptor read/64, error -71
[3684.388149] usb 3-2: new full speed USB device number 8 using uhci\_hcd
[3684.804118] usb 3-2: device not accepting address 8, error -71
[3684.916165] usb 3-2: new full speed USB device number 9 using uhci\_hcd
[3685.332120] usb 3-2: device not accepting address 9, error -71
[3759.876215] usb 3-1: new low speed USB device number 10 using uhci\_hcd
[3760.000096] usb 3-1: device descriptor read/64, error -71
[3760.228129] usb 3-1: device descriptor read/64, error -71
[3760.444141] usb 3-1: new low speed USB device number 11 using uhci\_hcd
[3760.624069] usb 3-1: device descriptor read/64, error -71
[3760.852114] usb 3-1: device descriptor read/64, error -71
[3761.068485] usb 3-1: new low speed USB device number 12 using uhci\_hcd
[3761.484194] usb 3-1: device not accepting address 12, error -71
[3761.596191] usb 3-1: new low speed USB device number 13 using uhci\_hcd
[3762.012153] usb 3-1: device not accepting address 13, error -71
[3922.256145] usb 3-1: new full speed USB device number 14 using uhci\_hcd
[3922.380116] usb 3-1: device descriptor read/64, error -71
[3922.604200] usb 3-1: device descriptor read/64, error -71
[3922.820117] usb 3-1: new full speed USB device number 15 using uhci\_hcd
[3922.940150] usb 3-1: device descriptor read/64, error -71
[3923.164156] usb 3-1: device descriptor read/64, error -71
[3923.380159] usb 3-1: new full speed USB device number 16 using uhci\_hcd
[3923.796075] usb 3-1: device not accepting address 16, error -71
[3923.908106] usb 3-1: new full speed USB device number 17 using uhci\_hcd
[3924.324122] usb 3-1: device not accepting address 17, error -71
[3985.374349] usb 1-2: USB disconnect, device number 7
[3987.440109] usb 2-2: new low speed USB device number 2 using uhci\_hcd
[3987.560527] usb 2-2: device descriptor read/64, error -71
[3987.840190] usb 2-2: device descriptor read/64, error -71
[3988.056151] usb 2-2: new low speed USB device number 3 using uhci\_hcd
[3988.180153] usb 2-2: device descriptor read/64, error -71
[3988.404129] usb 2-2: device descriptor read/64, error -71
[3988.620131] usb 2-2: new low speed USB device number 4 using uhci\_hcd
[3989.032135] usb 2-2: device not accepting address 4, error -71
[3989.145729] usb 2-2: new low speed USB device number 5 using uhci\_hcd
[3989.556106] usb 2-2: device not accepting address 5, error -71
[4090.164189] usb 2-2: new low speed USB device number 6 using uhci\_hcd
[4090.288205] usb 2-2: device descriptor read/64, error -71
[4090.512142] usb 2-2: device descriptor read/64, error -71
[4090.728513] usb 2-2: new low speed USB device number 7 using uhci\_hcd
[4090.908127] usb 2-2: device descriptor read/64, error -71
[4091.132157] usb 2-2: device descriptor read/64, error -71
[4091.348147] usb 2-2: new low speed USB device number 8 using uhci\_hcd
[4091.764112] usb 2-2: device not accepting address 8, error -71
[4091.932134] usb 2-2: new low speed USB device number 9 using uhci\_hcd
[4092.344109] usb 2-2: device not accepting address 9, error -71
[4094.324199] usb 3-2: new full speed USB device number 18 using uhci\_hcd
[4094.448159] usb 3-2: device descriptor read/64, error -71
[4094.728178] usb 3-2: device descriptor read/64, error -71
[4094.944181] usb 3-2: new full speed USB device number 19 using uhci\_hcd
[4095.064186] usb 3-2: device descriptor read/64, error -71
[4095.292106] usb 3-2: device descriptor read/64, error -71
[4095.508129] usb 3-2: new full speed USB device number 20 using uhci\_hcd
[4095.924124] usb 3-2: device not accepting address 20, error -71
[4096.036163] usb 3-2: new full speed USB device number 21 using uhci\_hcd
[4096.452187] usb 3-2: device not accepting address 21, error -71
[4105.312202] usb 2-2: new low speed USB device number 10 using uhci\_hcd
[4105.436181] usb 2-2: device descriptor read/64, error -71
[4105.664122] usb 2-2: device descriptor read/64, error -71
[4105.880178] usb 2-2: new low speed USB device number 11 using uhci\_hcd
[4106.004120] usb 2-2: device descriptor read/64, error -71
[4106.232133] usb 2-2: device descriptor read/64, error -71
[4106.448157] usb 2-2: new low speed USB device number 12 using uhci\_hcd
[4106.864092] usb 2-2: device not accepting address 12, error -71
[4106.976547] usb 2-2: new low speed USB device number 13 using uhci\_hcd
[4107.392102] usb 2-2: device not accepting address 13, error -71
[4115.720182] usb 2-2: new low speed USB device number 14 using uhci\_hcd
[4115.844181] usb 2-2: device descriptor read/64, error -71
[4116.072129] usb 2-2: device descriptor read/64, error -71
[4116.288158] usb 2-2: new low speed USB device number 15 using uhci\_hcd
[4116.412167] usb 2-2: device descriptor read/64, error -71
[4116.696137] usb 2-2: device descriptor read/64, error -71
[4116.912169] usb 2-2: new low speed USB device number 16 using uhci\_hcd
[4117.328137] usb 2-2: device not accepting address 16, error -71
[4117.440182] usb 2-2: new low speed USB device number 17 using uhci\_hcd
[4117.856138] usb 2-2: device not accepting address 17, error -71