大家好，我遇到的问题是，使用 USB C 扩展坞，我可以让我的笔记本电脑和 2 台显示器工作，但第 3 台显示器只能作为第二台外接显示器的镜像，所以我想知道我该怎么做才能让它工作：
当我断开并连接带有所有 2 个显示器的扩展坞时（顺便说一下，正常工作的是 HDMI，而作为镜像工作的第三个显示器通过 VGA 连接），从 dmesg 中可以看到：
[56652.087820] hid-generic 0005:046D:B342.000B: input,hidraw6: BLUETOOTH HID v42.00 Keyboard [Keyboard K380] on d0:c6:37:64:26:d8
[57847.906690] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906702] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906752] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906761] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906825] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906834] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906877] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.906885] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.935264] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.935274] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.935281] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57847.935288] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57849.782197] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57849.782211] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57849.782219] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57849.782227] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57850.722936] usb usb3: root hub lost power or was reset
[57850.722942] usb usb4: root hub lost power or was reset
[57863.222406] usb 1-5: new full-speed USB device number 10 using xhci_hcd
[57863.382923] usb 1-5: New USB device found, idVendor=177a, idProduct=963d, bcdDevice= 1.00
[57863.382931] usb 1-5: New USB device strings: Mfr=2, Product=3, SerialNumber=1
[57863.382936] usb 1-5: Product: Billboard Device
[57863.382940] usb 1-5: Manufacturer: EXPSM USB
[57863.382944] usb 1-5: SerialNumber: 0001
[57863.391244] hid-generic 0003:177A:963D.000C: hiddev0,hidraw7: USB HID v1.10 Device [EXPSM USB Billboard Device] on usb-0000:00:14.0-5/input0
[57865.275799] usb 1-5: USB disconnect, device number 10
[57865.403873] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.403913] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404060] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404089] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404223] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404251] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404378] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.404405] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.923607] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.923644] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.923674] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
[57865.923696] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected
djr@djacamo840:~$
当我拔下 vga 时似乎什么也没有发生，除了这些行之外：
[57865.923696] evdi: [D] evdi_detect:94 (dev=0) poll connector state: disconnected