我使用外部 USB 3.0 PCIe 卡。它在 13.10 上曾经运行良好。但自从升级到 14.04 后，热插拔似乎不再起作用了。它以前可以正常工作。
仅当在启动时插入此卡时它才能工作。dmesg 显示：03：00.0 USB 控制器：NEC Corporation uPD720200 USB 3.0 主机控制器（rev 03）
在操作过程中插入电源时，我只收到一条消息，提示发生了热插拔事件。除此之外，没有发生任何事。
知道为什么吗？
编辑2014-06-14：
我一直在 /var/log 文件夹中搜索。
在我看来，内核在热插拔期间根本无法识别该卡
安装 PCIe 外部卡后启动
lspci 命令：
03:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03)
/var/log/dmesg：
[ 1.314043] xhci_hcd 0000:03:00.0: xHCI Host Controller
[ 1.314049] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 3
[ 1.314343] xhci_hcd 0000:03:00.0: irq 42 for MSI/MSI-X
[ 1.314350] xhci_hcd 0000:03:00.0: irq 43 for MSI/MSI-X
[ 1.314356] xhci_hcd 0000:03:00.0: irq 44 for MSI/MSI-X
[ 1.314362] xhci_hcd 0000:03:00.0: irq 45 for MSI/MSI-X
[ 1.314369] xhci_hcd 0000:03:00.0: irq 46 for MSI/MSI-X
[ 1.314544] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002
[ 1.314546] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.314548] usb usb3: Product: xHCI Host Controller
[ 1.314549] usb usb3: Manufacturer: Linux 3.13.0-30-generic xhci_hcd
[ 1.314551] usb usb3: SerialNumber: 0000:03:00.0
[ 1.314658] hub 3-0:1.0: USB hub found
[ 1.314672] hub 3-0:1.0: 2 ports detected
[ 1.314742] xhci_hcd 0000:03:00.0: xHCI Host Controller
[ 1.314746] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 4
[ 1.317621] usb usb4: New USB device found, idVendor=1d6b, idProduct=0003
[ 1.317622] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1.317624] usb usb4: Product: xHCI Host Controller
[ 1.317625] usb usb4: Manufacturer: Linux 3.13.0-30-generic xhci_hcd
[ 1.317627] usb usb4: SerialNumber: 0000:03:00.0
[ 1.317700] hub 4-0:1.0: USB hub found
[ 1.317713] hub 4-0:1.0: 2 ports detected
/var/log/sys.log：（插入外部 USB 3.o 硬盘时的内核消息）
Jun 14 15:19:09 marina711 kernel: [ 403.002797] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
Jun 14 15:19:09 marina711 kernel: [ 403.020710] usb 4-1: Parent hub missing LPM exit latency info. Power management will be impacted.
Jun 14 15:19:09 marina711 kernel: [ 403.023650] usb 4-1: New USB device found, idVendor=0480, idProduct=a00d
Jun 14 15:19:09 marina711 kernel: [ 403.023661] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jun 14 15:19:09 marina711 kernel: [ 403.023667] usb 4-1: Product: External USB 3.0
Jun 14 15:19:09 marina711 kernel: [ 403.023672] usb 4-1: Manufacturer: TOSHIBA
Jun 14 15:19:09 marina711 kernel: [ 403.023677] usb 4-1: SerialNumber: 23183A26B28E
Jun 14 15:19:09 marina711 mtp-probe: checking bus 4, device 2: "/sys/devices/pci0000:00/0000:00:1c.2/0000:03:00.0/usb4/4-1"
Jun 14 15:19:09 marina711 mtp-probe: bus: 4, device: 2 was not an MTP device
Jun 14 15:19:09 marina711 kernel: [ 403.047210] usb-storage 4-1:1.0: USB Mass Storage device detected
Jun 14 15:19:09 marina711 kernel: [ 403.047466] scsi6 : usb-storage 4-1:1.0
Jun 14 15:19:09 marina711 kernel: [ 403.047575] usbcore: registered new interface driver usb-storage
Jun 14 15:19:13 marina711 kernel: [ 406.305836] scsi 6:0:0:0: Direct-Access TOSHIBA External USB 3.0 5438 PQ: 0 ANSI: 6
Jun 14 15:19:13 marina711 kernel: [ 406.306478] sd 6:0:0:0: Attached scsi generic sg2 type 0
Jun 14 15:19:13 marina711 kernel: [ 406.307703] sd 6:0:0:0: [sdc] 1953525164 512-byte logical blocks: (1.00 TB/931 GiB)
Jun 14 15:19:13 marina711 kernel: [ 406.308102] sd 6:0:0:0: [sdc] Write Protect is off
Jun 14 15:19:13 marina711 kernel: [ 406.308106] sd 6:0:0:0: [sdc] Mode Sense: 23 00 00 00
Jun 14 15:19:13 marina711 kernel: [ 406.308805] sd 6:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Jun 14 15:19:13 marina711 kernel: [ 406.317164] sdc: sdc1
Jun 14 15:19:13 marina711 kernel: [ 406.344720] sd 6:0:0:0: [sdc] Attached SCSI disk
/var/日志/udev：
UDEV [4.174356] add /devices/pci0000:00/0000:00:1c.2/0000:03:00.0 (pci)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1c.2/0000:03:00.0
DRIVER=xhci_hcd
ID_MODEL_FROM_DATABASE=uPD720200 USB 3.0 Host Controller
ID_PCI_CLASS_FROM_DATABASE=Serial bus controller
ID_PCI_INTERFACE_FROM_DATABASE=XHCI
ID_PCI_SUBCLASS_FROM_DATABASE=USB controller
ID_VENDOR_FROM_DATABASE=NEC Corporation
MODALIAS=pci:v00001033d00000194sv0000FFFFsd0000FFFFbc0Csc03i30
PCI_CLASS=C0330
PCI_ID=1033:0194
PCI_SLOT_NAME=0000:03:00.0
PCI_SUBSYS_ID=FFFF:FFFF
SEQNUM=1666
SUBSYSTEM=pci
USEC_INITIALIZED=85
卡热插拔消息：
lspci：未找到任何内容
/var/log/dmesg：未找到任何内容
dmesg 命令：
[ 31.456256] ACPI: \_SB_.PCI0: Bus check notify on hotplug_event_root
/var/log/kern.log：未找到任何内容
/var/log/sys.log：未找到任何内容
/var/log/udev：未找到任何内容
拔下电源后的 dmesg 命令：
[ 719.603717] ACPI: \_SB_.PCI0: Bus check notify on hotplug_event_root
比较两种情况下 lsmod 上加载的模块：未发现差异
如果在启动时插入卡，它会出现在 lspci 上。然后当我拔下它时，它仍然在那里！