Googling around, I found this: bluetooth controller not showing up in lsusb but showing up in dmesg
Then, I tried:
# dmesg | grep -i usb
5.350180] ACPI: bus type USB registered
5.350209] usbcore: registered new interface driver usbfs
5.350222] usbcore: registered new interface driver hub
5.350247] usbcore: registered new device driver usb
5.354655] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 1
5.355119] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
5.357118] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
5.357120] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
5.357121] usb usb1: Product: xHCI Host Controller
5.357122] usb usb1: Manufacturer: Linux 4.4.62-18.6-default xhci-hcd
5.357122] usb usb1: SerialNumber: 0000:00:14.0
5.357277] hub 1-0:1.0: USB hub found
5.359183] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 2
5.359233] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
5.359234] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
5.359235] usb usb2: Product: xHCI Host Controller
5.359236] usb usb2: Manufacturer: Linux 4.4.62-18.6-default xhci-hcd
5.359237] usb usb2: SerialNumber: 0000:00:14.0
5.359372] hub 2-0:1.0: USB hub found
5.359962] usb: port power management may be unreliable
5.360182] ehci-pci 0000:00:1d.0: new USB bus registered, assigned bus number 3
5.374624] ehci-pci 0000:00:1d.0: USB 2.0 started, EHCI 1.00
5.374676] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002
5.374678] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1
5.374679] usb usb3: Product: EHCI Host Controller
5.374680] usb usb3: Manufacturer: Linux 4.4.62-18.6-default ehci_hcd
5.374680] usb usb3: SerialNumber: 0000:00:1d.0
5.374860] hub 3-0:1.0: USB hub found
5.574661] usb 2-2: new SuperSpeed USB device number 2 using xhci_hcd
5.591054] usb 2-2: New USB device found, idVendor=0424, idProduct=5537
5.591056] usb 2-2: New USB device strings: Mfr=2, Product=3, SerialNumber=0
5.591056] usb 2-2: Product: USB5537B
5.591057] usb 2-2: Manufacturer: SMSC
5.591609] hub 2-2:1.0: USB hub found
5.686633] usb 3-1: new high-speed USB device number 2 using ehci-pci
5.706629] usb 1-2: new high-speed USB device number 2 using xhci_hcd
5.819053] usb 3-1: New USB device found, idVendor=8087, idProduct=8001
5.819056] usb 3-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
5.819337] hub 3-1:1.0: USB hub found
5.838988] usb 1-2: New USB device found, idVendor=0424, idProduct=2137
5.838990] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
5.838992] usb 1-2: Product: USB2137B
5.838993] usb 1-2: Manufacturer: SMSC
5.839317] hub 1-2:1.0: USB hub found
6.006708] usb 1-5: new full-speed USB device number 3 using xhci_hcd
6.135872] usb 1-5: New USB device found, idVendor=04ca, idProduct=3014
6.135875] usb 1-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
6.206710] usb 1-2.1: new high-speed USB device number 4 using xhci_hcd
6.295317] usb 1-2.1: New USB device found, idVendor=2357, idProduct=010d
6.295320] usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
6.295321] usb 1-2.1: Product: 802.11n NIC
6.295322] usb 1-2.1: Manufacturer: Realtek
6.295323] usb 1-2.1: SerialNumber: 123456
6.406713] usb 1-7: new high-speed USB device number 5 using xhci_hcd
6.543952] usb 1-7: New USB device found, idVendor=1bcf, idProduct=2c81
6.543956] usb 1-7: New USB device strings: Mfr=1, Product=2, SerialNumber=0
6.543957] usb 1-7: Product: HD WebCam
6.543957] usb 1-7: Manufacturer: NC2141103M50708908LM05
6.610716] usb 1-2.2: new full-speed USB device number 6 using xhci_hcd
6.704291] usb 1-2.2: New USB device found, idVendor=045e, idProduct=0745
6.704295] usb 1-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
6.704296] usb 1-2.2: Product: Microsoft® 2.4GHz Transceiver v8.0
6.704297] usb 1-2.2: Manufacturer: Microsoft
6.720756] usbcore: registered new interface driver usbhid
6.720758] usbhid: USB HID core driver
6.725488] input: Microsoft Microsoft® 2.4GHz Transceiver v8.0 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.0/0003:045E:0745.0001/input/input6
6.778833] hid-generic 0003:045E:0745.0001: input,hidraw0: USB HID v1.11 Keyboard [Microsoft Microsoft® 2.4GHz Transceiver v8.0] on usb-0000:00:14.0-2.2/input0
6.779204] input: Microsoft Microsoft® 2.4GHz Transceiver v8.0 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.1/0003:045E:0745.0002/input/input7
6.810665] usb 1-8: new high-speed USB device number 7 using xhci_hcd
6.834775] hid-generic 0003:045E:0745.0002: input,hidraw1: USB HID v1.11 Mouse [Microsoft Microsoft® 2.4GHz Transceiver v8.0] on usb-0000:00:14.0-2.2/input1
6.844958] input: Microsoft Microsoft® 2.4GHz Transceiver v8.0 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.2/0003:045E:0745.0003/input/input8
6.898994] hid-generic 0003:045E:0745.0003: input,hiddev0,hidraw2: USB HID v1.11 Device [Microsoft Microsoft® 2.4GHz Transceiver v8.0] on usb-0000:00:14.0-2.2/input2
6.939239] usb 1-8: New USB device found, idVendor=0bda, idProduct=0129
6.939242] usb 1-8: New USB device strings: Mfr=1, Product=2, SerialNumber=3
6.939245] usb 1-8: Product: USB2.0-CRW
6.939247] usb 1-8: Manufacturer: Generic
6.939248] usb 1-8: SerialNumber: 20100201396000000
6.945781] usbcore: registered new interface driver rtsx_usb
18.318545] usb 1-5: USB disconnect, device number 3
22.649268] input: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input19
22.649339] usbcore: registered new interface driver uvcvideo
22.649339] USB Video Class driver (1.1.1)
22.797181] usbcore: registered new interface driver btusb
23.195793] usbcore: registered new interface driver ath3k
23.506222] usbcore: registered new interface driver rtl8812au
See those lines?
# dmesg | grep 'usb 1-5'
6.006708] usb 1-5: new full-speed USB device number 3 using xhci_hcd
6.135872] usb 1-5: New USB device found, idVendor=04ca, idProduct=3014
6.135875] usb 1-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
18.318545] usb 1-5: USB disconnect, device number 3
What does dmesg mean by found and then disconnect???