为什么使用 lsusb 命令时没有列出我的打印机？
我在 Ubuntu 12.04 上通过 USB 连接了一台 HP Photosmart C4780。我安装了 hplip，但问题仍然没有解决。打印机未显示在打印机列表中。
我如何添加打印机？
谢谢。
编辑-使用 dmesg | tail -f：
连接打印机之前
[15358.944014] usb 1-1.4: device descriptor read/all, error -71
[15359.015787] usb 1-1.4: new high-speed USB device number 12 using ehci_hcd
[15359.119684] usb 1-1.4: device descriptor read/all, error -71
[15359.191166] usb 1-1.4: new high-speed USB device number 13 using ehci_hcd
[15359.223171] usb 1-1.4: device descriptor read/8, error -71
[15359.354968] usb 1-1.4: device descriptor read/8, error -71
[15359.530444] usb 1-1.4: new high-speed USB device number 14 using ehci_hcd
[15359.562288] usb 1-1.4: device descriptor read/8, error -71
[15359.694434] usb 1-1.4: device descriptor read/8, error -71
[15359.797753] hub 1-1:1.0: unable to enumerate USB device on port 4
插入后：
[15498.352933] usb 1-1.4: device descriptor read/all, error -71
[15498.424509] usb 1-1.4: new high-speed USB device number 16 using ehci_hcd
[15498.528717] usb 1-1.4: device descriptor read/all, error -71
[15498.600251] usb 1-1.4: new high-speed USB device number 17 using ehci_hcd
[15498.632144] usb 1-1.4: device descriptor read/8, error -71
[15498.763804] usb 1-1.4: device descriptor read/8, error -71
[15498.939336] usb 1-1.4: new high-speed USB device number 18 using ehci_hcd
[15498.971263] usb 1-1.4: device descriptor read/8, error -71
[15499.103217] usb 1-1.4: device descriptor read/8, error -71
[15499.206663] hub 1-1:1.0: unable to enumerate USB device on port 4