我在使用 Ubuntu 17.10。我连接 iPad 并“信任这台电脑”。它安装正常，我可以将文件复制到 iPad 上。
然后我将其卸载（单击 Nemo 中的“弹出”按钮），如果我尝试再次连接，Ubuntu 会发出声音，但它不会安装。
如果我随后更换为另一个 USB 端口，它就会连接，但再次断开连接后，它不会再安装在任何使用的 USB 端口上。一旦我没有 USB 端口，我必须重新启动 Ubuntu 才能使其再次工作。
我不确定在哪里可以找到问题解决方案，但这是 dmesg 的最后几行
[ 123.396321] usb 1-2: new high-speed USB device number 4 using xhci_hcd[ 123.541075] usb 1-2: New USB device found, idVendor=05ac, idProduct=12ab
[ 123.541085] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 123.541091] usb 1-2: Product: iPad
[ 123.541098] usb 1-2: Manufacturer: Apple Inc.
[ 123.541104] usb 1-2: SerialNumber: f4502336fbe696c3d4e8571331f5e803c39037a6
[ 124.964359] ipheth 1-2:4.2: Apple iPhone USB Ethernet device attached
[ 124.964439] usbcore: registered new interface driver ipheth
[ 124.972213] ipheth 1-2:4.2 enp0s20f0u2c4i2: renamed from eth0
[ 124.991443] IPv6: ADDRCONF(NETDEV_UP): enp0s20f0u2c4i2: link is not ready
[ 124.992044] IPv6: ADDRCONF(NETDEV_UP): enp0s20f0u2c4i2: link is not ready
[20569.516047] perf: interrupt took too long (2560 > 2500), lowering kernel.perf_event_max_sample_rate to 78000
[29842.636538] perf: interrupt took too long (3269 > 3200), lowering kernel.perf_event_max_sample_rate to 61000
[35579.994541] ipheth 1-2:4.2: ipheth_rcvbulk_callback: urb status: -71
[35579.995348] usb 1-2: USB disconnect, device number 4
[35580.035540] ipheth 1-2:4.2: Apple iPhone USB Ethernet now disconnected
[35870.631947] usb 1-2: new high-speed USB device number 5 using xhci_hcd
[35870.777588] usb 1-2: New USB device found, idVendor=05ac, idProduct=12ab
[35870.777598] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[35870.777605] usb 1-2: Product: iPad
[35870.777612] usb 1-2: Manufacturer: Apple Inc.
[35870.777617] usb 1-2: SerialNumber: f4502336fbe696c3d4e8571331f5e803c39037a6
[35876.099655] usb 1-2: USB disconnect, device number 5
[35881.111704] usb 1-1: new high-speed USB device number 6 using xhci_hcd
[35881.256954] usb 1-1: New USB device found, idVendor=05ac, idProduct=12ab
[35881.256965] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[35881.256972] usb 1-1: Product: iPad
[35881.256979] usb 1-1: Manufacturer: Apple Inc.
[35881.256984] usb 1-1: SerialNumber: f4502336fbe696c3d4e8571331f5e803c39037a6
[35881.339532] ipheth 1-1:4.2: Apple iPhone USB Ethernet device attached
[35881.359115] ipheth 1-1:4.2 enp0s20f0u1c4i2: renamed from eth0
[35881.611703] IPv6: ADDRCONF(NETDEV_UP): enp0s20f0u1c4i2: link is not ready
[35881.614659] IPv6: ADDRCONF(NETDEV_UP): enp0s20f0u1c4i2: link is not ready
[36101.825275] ipheth 1-1:4.2: ipheth_rcvbulk_callback: urb status: -71
[36101.825954] usb 1-1: USB disconnect, device number 6
[36101.859619] ipheth 1-1:4.2: Apple iPhone USB Ethernet now disconnected
[41730.499127] perf: interrupt took too long (4100 > 4086), lowering kernel.perf_event_max_sample_rate to 48750
[42929.614766] usb 1-1: new high-speed USB device number 7 using xhci_hcd
[42929.760395] usb 1-1: New USB device found, idVendor=05ac, idProduct=12ab
[42929.760405] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[42929.760412] usb 1-1: Product: iPad
[42929.760419] usb 1-1: Manufacturer: Apple Inc.
[42929.760424] usb 1-1: SerialNumber: f4502336fbe696c3d4e8571331f5e803c39037a6
编辑：我发现如果我运行这个：
sudo /usr/sbin/usbmuxd -U usbmux
iPad 无需重启即可安装。但为什么在 USB 端口使用一次没有问题后我还要手动执行此操作？