但是如果我尝试使用 cheese，它不会检测到网络摄像头。如果我运行命令 lsusb，它会给出以下输出：
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 1c7a:0570 LighTuning Technology Inc.
Bus 001 Device 002: ID 8087:0a2a Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
根本没有网络摄像头。但是如果我运行 dmesg | grep usb，则会得到以下信息：
[ 0.335304] usbcore: registered new interface driver usbfs
[ 0.335304] usbcore: registered new interface driver hub
[ 0.335304] usbcore: registered new device driver usb
[ 1.558595] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.04
[ 1.558596] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.558597] usb usb1: Product: xHCI Host Controller
[ 1.558599] usb usb1: Manufacturer: Linux 5.4.0-60-generic xhci-hcd
[ 1.558600] usb usb1: SerialNumber: 0000:00:14.0
[ 1.560485] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 5.04
[ 1.560486] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.560487] usb usb2: Product: xHCI Host Controller
[ 1.560488] usb usb2: Manufacturer: Linux 5.4.0-60-generic xhci-hcd
[ 1.560489] usb usb2: SerialNumber: 0000:00:14.0
[ 1.561081] usb: port power management may be unreliable
[ 1.898682] usb 1-5: new full-speed USB device number 2 using xhci_hcd
[ 2.047737] usb 1-5: New USB device found, idVendor=8087, idProduct=0a2a, bcdDevice= 0.01
[ 2.047739] usb 1-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 2.174261] usb 1-9: new full-speed USB device number 3 using xhci_hcd
[ 2.325707] usb 1-9: New USB device found, idVendor=1c7a, idProduct=0570, bcdDevice=10.41
[ 2.325710] usb 1-9: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2.325712] usb 1-9: Product: EgisTec Touch Fingerprint Sensor
[ 2.325713] usb 1-9: Manufacturer: EgisTec
[ 2.325714] usb 1-9: SerialNumber: GE0CDD1F
[ 4.141540] usbcore: registered new interface driver btusb
[ 1541.348296] usbcore: registered new interface driver uvcvideo
[ 1684.680129] usb 1-7: new high-speed USB device number 4 using xhci_hcd
[ 1684.855718] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 1684.855724] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1684.855727] usb 1-7: Product: HD WebCam
[ 1684.855730] usb 1-7: Manufacturer: Generic
[ 1684.855732] usb 1-7: SerialNumber: 200901010001
[ 1684.876210] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input19
[ 1691.137979] usb 1-7: USB disconnect, device number 4
[ 1719.377673] usb 1-7: new high-speed USB device number 5 using xhci_hcd
[ 1719.549133] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 1719.549139] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1719.549143] usb 1-7: Product: HD WebCam
[ 1719.549146] usb 1-7: Manufacturer: Generic
[ 1719.549149] usb 1-7: SerialNumber: 200901010001
[ 1719.562388] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input20
[ 1722.802176] usb 1-7: USB disconnect, device number 5
[ 1729.138249] usb 1-7: new high-speed USB device number 6 using xhci_hcd
[ 1729.310772] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 1729.310779] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1729.310782] usb 1-7: Product: HD WebCam
[ 1729.310785] usb 1-7: Manufacturer: Generic
[ 1729.310788] usb 1-7: SerialNumber: 200901010001
[ 1729.324657] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input21
[ 1732.470691] usb 1-7: USB disconnect, device number 6
[ 1739.039036] usb 1-7: new high-speed USB device number 7 using xhci_hcd
[ 1739.214844] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 1739.214851] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1739.214855] usb 1-7: Product: HD WebCam
[ 1739.214857] usb 1-7: Manufacturer: Generic
[ 1739.214860] usb 1-7: SerialNumber: 200901010001
[ 1739.232304] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input22
[ 1743.254860] usb 1-7: USB disconnect, device number 7
[ 1748.143734] usb 1-7: new high-speed USB device number 8 using xhci_hcd
[ 1748.323128] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 1748.323133] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 1748.323136] usb 1-7: Product: HD WebCam
[ 1748.323139] usb 1-7: Manufacturer: Generic
[ 1748.323141] usb 1-7: SerialNumber: 200901010001
[ 1748.343508] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input23
[ 1750.910125] usb 1-7: USB disconnect, device number 8
[ 2200.689002] usb 1-7: new high-speed USB device number 9 using xhci_hcd
[ 2200.867050] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 2200.867055] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 2200.867059] usb 1-7: Product: HD WebCam
[ 2200.867061] usb 1-7: Manufacturer: Generic
[ 2200.867064] usb 1-7: SerialNumber: 200901010001
[ 2200.897296] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input24
[ 2203.423790] usb 1-7: USB disconnect, device number 9
[ 2203.747318] usb 1-7: new high-speed USB device number 10 using xhci_hcd
[ 2203.926608] usb 1-7: New USB device found, idVendor=04f2, idProduct=b5c5, bcdDevice=96.18
[ 2203.926614] usb 1-7: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 2203.926618] usb 1-7: Product: HD WebCam
[ 2203.926621] usb 1-7: Manufacturer: Generic
[ 2203.926623] usb 1-7: SerialNumber: 200901010001
[ 2203.955649] input: HD WebCam: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/input/input25
系统信息：
Linux 5.4.0-60-generic #67~18.04.1-Ubuntu SMP Tue Jan 5 22:01:05 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
您可以清楚地看到有一个网络摄像头，但我不知道它出了什么问题。感谢您的帮助！
编辑：
lena@lena-pc:~$ sudo journalctl -b 0
-- Logs begin at Sun 2019-12-22 14:48:21 CET, end at Fri 2021-01-15 09:21:24 CET. --
Jan 14 18:29:17 lena-pc kernel: microcode: microcode updated early to revision 0xe0, date = 2020-06-17
Jan 14 18:29:17 lena-pc kernel: Linux version 5.4.0-60-generic (buildd@lgw01-amd64-007) (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #67~1
Jan 14 18:29:17 lena-pc kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-5.4.0-60-generic root=UUID=e0831188-19af-4ae7-982d-3aef4c5d8417 ro quiet
Jan 14 18:29:17 lena-pc kernel: KERNEL supported cpus:
Jan 14 18:29:17 lena-pc kernel: Intel GenuineIntel
Jan 14 18:29:17 lena-pc kernel: AMD AuthenticAMD
Jan 14 18:29:17 lena-pc kernel: Hygon HygonGenuine
Jan 14 18:29:17 lena-pc kernel: Centaur CentaurHauls
Jan 14 18:29:17 lena-pc kernel: zhaoxin Shanghai
Jan 14 18:29:17 lena-pc kernel: x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
Jan 14 18:29:17 lena-pc kernel: x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
Jan 14 18:29:17 lena-pc kernel: x86/fpu: Supporting XSAVE feature 0x008: 'MPX bounds registers'
Jan 14 18:29:17 lena-pc kernel: x86/fpu: Supporting XSAVE feature 0x010: 'MPX CSR'
Jan 14 18:29:17 lena-pc kernel: x86/fpu: xstate_offset[3]: 576, xstate_sizes[3]: 64
Jan 14 18:29:17 lena-pc kernel: x86/fpu: xstate_offset[4]: 640, xstate_sizes[4]: 64
Jan 14 18:29:17 lena-pc kernel: x86/fpu: Enabled xstate features 0x1b, context size is 704 bytes, using 'compacted' format.
Jan 14 18:29:17 lena-pc kernel: BIOS-provided physical RAM map:
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x0000000000058000-0x0000000000058fff] reserved
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x0000000000059000-0x000000000009dfff] usable
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x000000000009e000-0x00000000000fffff] reserved
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000723cefff] usable
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x00000000723cf000-0x00000000723cffff] ACPI NVS
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x00000000723d0000-0x00000000723d0fff] reserved
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x00000000723d1000-0x0000000089c9dfff] usable
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x0000000089c9e000-0x000000008a88dfff] reserved
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x000000008a88e000-0x000000008af7dfff] ACPI NVS
Jan 14 18:29:17 lena-pc kernel: BIOS-e820: [mem 0x000000008af7e000-0x000000008affdfff] ACPI data
须藤lshw
*-usbhost:0
Produkt: xHCI Host Controller
Hersteller: Linux 5.4.0-60-generic xhci-hcd
Physische ID: 0
Bus-Informationen: usb@1
Logischer Name: usb1
Version: 5.04
Fähigkeiten: usb-2.00
Konfiguration: driver=hub slots=12 speed=480Mbit/s
*-usb:0
Beschreibung: Bluetooth-Schnittstelle
Hersteller: Intel Corp.
Physische ID: 5
Bus-Informationen: usb@1:5
Version: 0.01
Fähigkeiten: bluetooth usb-2.01
Konfiguration: driver=btusb maxpower=100mA speed=12Mbit/s
*-usb:1 UNGEFORDERT
Beschreibung: Allgemeines USB-Gerät
Produkt: EgisTec Touch Fingerprint Sensor
Hersteller: EgisTec
Physische ID: 9
Bus-Informationen: usb@1:9
Version: 10.41
Seriennummer: GE0CDD1F
Fähigkeiten: usb-1.10
Konfiguration: maxpower=100mA speed=12Mbit/s
*-usbhost:1
Produkt: xHCI Host Controller
Hersteller: Linux 5.4.0-60-generic xhci-hcd
Physische ID: 1
Bus-Informationen: usb@2
Logischer Name: usb2
Version: 5.04
Fähigkeiten: usb-3.00
Konfiguration: driver=hub slots=6 speed=5000Mbit/s