I have the same problem on my Ubuntu Server Ubuntu 14.04.3 LTS (GNU/Linux 3.13.0-63-generic x86_64)
Plug in a USB 3 powered drive and I get: Sep 16 14:38:16 fuller kernel: [ 258.785743] usb 3-4: new full-speed USB device number 2 using xhci_hcd Sep 16 14:38:16 fuller kernel: [ 258.785913] usb 3-4: Device not responding to set address. Sep 16 14:38:16 fuller kernel: [ 258.989962] usb 3-4: Device not responding to set address. Sep 16 14:38:16 fuller kernel: [ 259.193931] usb 3-4: device not accepting address 2, error -71 Sep 16 14:38:16 fuller kernel: [ 259.305981] usb 3-4: new full-speed USB device number 3 using xhci_hcd Sep 16 14:38:16 fuller kernel: [ 259.306146] usb 3-4: Device not responding to set address. Sep 16 14:38:17 fuller kernel: [ 259.510201] usb 3-4: Device not responding to set address. Sep 16 14:38:17 fuller kernel: [ 259.714169] usb 3-4: device not accepting address 3, error -71 Sep 16 14:38:17 fuller kernel: [ 259.826218] usb 3-4: new full-speed USB device number 4 using xhci_hcd Sep 16 14:38:17 fuller kernel: [ 259.826387] usb 3-4: Device not responding to set address. Sep 16 14:38:17 fuller kernel: [ 260.030471] usb 3-4: Device not responding to set address. Sep 16 14:38:17 fuller kernel: [ 260.234411] usb 3-4: device not accepting address 4, error -71 Sep 16 14:38:17 fuller kernel: [ 260.346462] usb 3-4: new full-speed USB device number 5 using xhci_hcd Sep 16 14:38:17 fuller kernel: [ 260.346624] usb 3-4: Device not responding to set address. Sep 16 14:38:18 fuller kernel: [ 260.550715] usb 3-4: Device not responding to set address. Sep 16 14:38:18 fuller kernel: [ 260.754648] usb 3-4: device not accepting address 5, error -71 Sep 16 14:38:18 fuller kernel: [ 260.754749] hub 3-0:1.0: unable to enumerate USB device on port 4 politas@fuller:~$ lsusb -t /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M |__ Port 6: Dev 3, If 0, Class=Vendor Specific Class, Driver=usbfs, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M |__ Port 3: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M Tried the autosuspend workaround mentioned above with no change. How do we undo that, by the way? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1242321 Title: USB 3.0 Harddrive not recognised Status in linux package in Ubuntu: Confirmed Bug description: Ubuntu is not recognising any device plugged into any USB 3.0 ports. Sometimes Ubuntu will freeze for a few seconds when you plug something into a USB 3.0 port; when Ubuntu comes out of the freeze, the device is still NOT recognised. No problems with USB 2.0 ports and devices. The USB 3.0 on this computer only works in Windows 7 (I'm dual booting Ubuntu 13.10 and Windows 7, both are 64-bit). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1242321/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp