Eu tenho um problema com meu laptop asus em ter apenas um usb3.0 e funciona, às vezes ... às vezes ele simplesmente morre.
$ dmesg | grep xhci_hcd
[ 1.488284] xhci_hcd 0000:04:00.0: xHCI Host Controller
[ 1.488289] xhci_hcd 0000:04:00.0: new USB bus registered, assigned bus number 3
[ 1.499021] xhci_hcd 0000:04:00.0: irq 45 for MSI/MSI-X
[ 1.499027] xhci_hcd 0000:04:00.0: irq 46 for MSI/MSI-X
[ 1.499033] xhci_hcd 0000:04:00.0: irq 47 for MSI/MSI-X
[ 1.499039] xhci_hcd 0000:04:00.0: irq 48 for MSI/MSI-X
[ 1.499045] xhci_hcd 0000:04:00.0: irq 49 for MSI/MSI-X
[ 1.499052] xhci_hcd 0000:04:00.0: irq 50 for MSI/MSI-X
[ 1.499058] xhci_hcd 0000:04:00.0: irq 51 for MSI/MSI-X
[ 1.499063] xhci_hcd 0000:04:00.0: irq 52 for MSI/MSI-X
[ 1.499205] usb usb3: Manufacturer: Linux 3.11.0-20-generic xhci_hcd
[ 1.499349] xhci_hcd 0000:04:00.0: xHCI Host Controller
[ 1.499352] xhci_hcd 0000:04:00.0: new USB bus registered, assigned bus number 4
[ 1.499391] usb usb4: Manufacturer: Linux 3.11.0-20-generic xhci_hcd
[48439.672080] usb 3-1: new high-speed USB device number 2 using xhci_hcd
[48439.984535] usb 3-1.1: new high-speed USB device number 3 using xhci_hcd
[48440.096651] usb 3-1.2: new full-speed USB device number 4 using xhci_hcd
[48440.216924] usb 3-1.3: new high-speed USB device number 5 using xhci_hcd
[48440.320911] usb 3-1.4: new full-speed USB device number 6 using xhci_hcd
[48440.452843] usb 3-1.1.4: new high-speed USB device number 7 using xhci_hcd
[48440.808690] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
[48441.438322] usb 4-1.1: new SuperSpeed USB device number 3 using xhci_hcd
[48442.070953] usb 4-1.1.1: new SuperSpeed USB device number 4 using xhci_hcd
[48450.478931] xhci_hcd 0000:04:00.0: xHCI host not responding to stop endpoint command.
[48450.478938] xhci_hcd 0000:04:00.0: Assuming host is dying, halting host.
[48450.478982] xhci_hcd 0000:04:00.0: HC died; cleaning up
[48453.478077] xhci_hcd 0000:04:00.0: Timeout while waiting for configure endpoint command
[48453.478087] xhci_hcd 0000:04:00.0: Abort the command ring, but the xHCI is dead.
Mesmo a reinicialização não pode ajudar, apenas desligue / ligue. Com usb 2.0 está tudo bem Laptop modelo k53s. Kernel Linux mf-laptop 3.11.0-20-genérico # 35-Ubuntu SMP Sex 2 de maio 21:32:49 UTC 2014 x86_64 x86_64 x86_64 GNU / Linux
E também não está claro como colocar esse tipo de bug no bugzilla. Eu escrevi também suporte técnico asus dizem que a atualização do driver vai ajudar apenas problema é que este driver para win7.