plug in cp2101 device,
cat /dev/ttyUSB0
unplug device

usb 1-1: new full speed USB device using uhci_hcd and address 6
usb 1-1: new device found, idVendor=10ab, idProduct=10c5
usb 1-1: new device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: usb data cable
usb 1-1: Manufacturer: Silicon Labs
usb 1-1: SerialNumber: 0001
usb 1-1: configuration #1 chosen from 1 choice
cp2101 1-1:1.0: cp2101 converter detected
usb 1-1: reset full speed USB device using uhci_hcd and address 6
usb 1-1: cp2101 converter now attached to ttyUSB0
usb 1-1: USB disconnect, address 6
cp2101 1-1:1.0: device disconnected
cp2101 ttyUSB0: cp2101_set_config - Unable to send request, request=0x0 size=2 result=-19
cp2101 ttyUSB0: cp2101 converter now disconnected from ttyUSB0
Slab corruption: start=c2131a04, len=1024
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c020a41e>](device_release+0x14/0x41)
010: 6b 6b 6b 6b 6b 6b 6b 6b 6c 6b 6b 6b 6b 6b 6b 6b
Prev obj: start=c21315f8, len=1024
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c022fe1f>](kfree_skbmem+0x8/0x5f)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b