J'ai exécuté la commande
dmesg | grep usb
et ça donne ceci :
zenbook:~$ dmesg | grep usb
[ 0.132598] usbcore: registered new interface driver usbfs
[ 0.132598] usbcore: registered new interface driver hub
[ 0.132598] usbcore: registered new device driver usb
[ 1.026350] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[ 1.026351] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.026352] usb usb1: Product: xHCI Host Controller
[ 1.026353] usb usb1: Manufacturer: Linux 4.15.0-112-generic xhci-hcd
[ 1.026354] usb usb1: SerialNumber: 0000:00:14.0
[ 1.027350] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
[ 1.027351] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.027352] usb usb2: Product: xHCI Host Controller
[ 1.027353] usb usb2: Manufacturer: Linux 4.15.0-112-generic xhci-hcd
[ 1.027354] usb usb2: SerialNumber: 0000:00:14.0
[ 1.360465] usb 1-2: new full-speed USB device number 2 using xhci_hcd
[ 1.512085] usb 1-2: New USB device found, idVendor=046d, idProduct=c52b
[ 1.512086] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1.512087] usb 1-2: Product: USB Receiver
[ 1.512087] usb 1-2: Manufacturer: Logitech
[ 1.648869] usb 1-8: new full-speed USB device number 3 using xhci_hcd
[ 1.802154] usb 1-8: New USB device found, idVendor=8087, idProduct=0a2b
[ 1.802155] usb 1-8: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 1.814378] usbcore: registered new interface driver usbhid
[ 1.814379] usbhid: USB HID core driver
[ 1.865816] logitech-djreceiver 0003:046D:C52B.0003: hiddev0,hidraw0: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:14.0-2/input2
[ 1.987003] input: Logitech Unifying Device. Wireless PID:4009 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.2/0003:046D:C52B.0003/0003:046D:4009.0004/input/input6
[ 1.987110] hid-generic 0003:046D:4009.0004: input,hidraw1: USB HID v1.11 Mouse [Logitech Unifying Device. Wireless PID:4009] on usb-0000:00:14.0-2:1
[ 2.032901] input: Logitech M315/M235 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.2/0003:046D:C52B.0003/0003:046D:4009.0004/input/input7
[ 2.033296] logitech-hidpp-device 0003:046D:4009.0004: input,hidraw1: USB HID v1.11 Mouse [Logitech M315/M235] on usb-0000:00:14.0-2:1
[ 4.677075] usbcore: registered new interface driver btusb
[ 105.386577] usb 1-2: USB disconnect, device number 2
[ 149.067172] usb usb1: root hub lost power or was reset
[ 149.067176] usb usb2: root hub lost power or was reset
[ 149.425093] usb 1-8: reset full-speed USB device number 3 using xhci_hcd
[ 189.720098] usb 1-2: new full-speed USB device number 4 using xhci_hcd
[ 189.873449] usb 1-2: New USB device found, idVendor=046d, idProduct=c52b
[ 189.873457] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 189.873462] usb 1-2: Product: USB Receiver
[ 189.873467] usb 1-2: Manufacturer: Logitech
[ 189.888127] logitech-djreceiver 0003:046D:C52B.0008: hiddev0,hidraw0: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:14.0-2/input2
[ 190.022730] input: Logitech M315/M235 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.2/0003:046D:C52B.0008/0003:046D:4009.0009/input/input20
[ 190.023339] logitech-hidpp-device 0003:046D:4009.0009: input,hidraw1: USB HID v1.11 Mouse [Logitech M315/M235] on usb-0000:00:14.0-2:1
[ 192.299764] usb 1-2: USB disconnect, device number 4
[ 224.904438] usbcore: deregistering interface driver usbhid
[ 228.567351] usbcore: registered new interface driver usbhid
[ 228.567356] usbhid: USB HID core driver
[ 239.352420] usb 1-2: new full-speed USB device number 5 using xhci_hcd
[ 239.505461] usb 1-2: New USB device found, idVendor=046d, idProduct=c52b
[ 239.505467] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 239.505471] usb 1-2: Product: USB Receiver
[ 239.505475] usb 1-2: Manufacturer: Logitech
[ 239.517168] logitech-djreceiver 0003:046D:C52B.000C: hiddev0,hidraw0: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:14.0-2/input2
[ 239.654139] input: Logitech M315/M235 as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.2/0003:046D:C52B.000C/0003:046D:4009.000D/input/input21
[ 239.654688] logitech-hidpp-device 0003:046D:4009.000D: input,hidraw1: USB HID v1.11 Mouse [Logitech M315/M235] on usb-0000:00:14.0-2:1
[ 1732.277840] usb 1-3: new full-speed USB device number 6 using xhci_hcd
[ 1732.428140] usb 1-3: New USB device found, idVendor=04a9, idProduct=220e
[ 1732.428147] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1732.428151] usb 1-3: Product: CanoScan
[ 1732.428154] usb 1-3: Manufacturer: Canon
[ 1796.329518] usb 1-6: new high-speed USB device number 7 using xhci_hcd
[ 1796.512188] usb 1-6: New USB device found, idVendor=0bda, idProduct=58d2
[ 1796.512190] usb 1-6: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1796.512191] usb 1-6: Product: USB2.0 HD UVC WebCam
[ 1796.512192] usb 1-6: Manufacturer: 04081-0009590017051007186
[ 1796.512193] usb 1-6: SerialNumber: 200901010001
[ 1796.561854] input: USB2.0 HD UVC WebCam: USB2.0 HD as /devices/pci0000:00/0000:00:14.0/usb1/1-6/1-6:1.0/input/input22
[ 1796.561988] usbcore: registered new interface driver uvcvideo
[ 1799.113761] usb 1-6: USB disconnect, device number 7
[ 1835.299385] usb 1-3: USB disconnect, device number 6
[ 1865.393485] usb 1-1: new full-speed USB device number 8 using xhci_hcd
[ 1865.543864] usb 1-1: New USB device found, idVendor=04a9, idProduct=220e
[ 1865.543871] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1865.543876] usb 1-1: Product: CanoScan
[ 1865.543879] usb 1-1: Manufacturer: Canon
[ 1918.666740] usb 1-1: USB disconnect, device number 8
[ 1924.577895] usb 1-8: reset full-speed USB device number 3 using xhci_hcd
[ 1929.913770] usb 1-6: new high-speed USB device number 9 using xhci_hcd
[ 1930.096852] usb 1-6: New USB device found, idVendor=0bda, idProduct=58d2
[ 1930.096859] usb 1-6: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1930.096863] usb 1-6: Product: USB2.0 HD UVC WebCam
[ 1930.096867] usb 1-6: Manufacturer: 04081-0009590017051007186
[ 1930.096870] usb 1-6: SerialNumber: 200901010001
[ 1930.105244] input: USB2.0 HD UVC WebCam: USB2.0 HD as /devices/pci0000:00/0000:00:14.0/usb1/1-6/1-6:1.0/input/input23
[ 1932.229597] usb 1-6: USB disconnect, device number 9
[ 3420.064950] usb 1-6: new high-speed USB device number 10 using xhci_hcd
[ 3420.247691] usb 1-6: New USB device found, idVendor=0bda, idProduct=58d2
[ 3420.247697] usb 1-6: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 3420.247701] usb 1-6: Product: USB2.0 HD UVC WebCam
[ 3420.247705] usb 1-6: Manufacturer: 04081-0009590017051007186
[ 3420.247708] usb 1-6: SerialNumber: 200901010001
[ 3420.255869] input: USB2.0 HD UVC WebCam: USB2.0 HD as /devices/pci0000:00/0000:00:14.0/usb1/1-6/1-6:1.0/input/input24
[ 3423.188852] usb 1-6: USB disconnect, device number 10
Si je comprends bien la caméra est déconnectée mais elle est bien là.