James Cloos wrote in comment 34: > Switching to the performance govenor, removing the drive and re-adding it > worked around the bug. > > Something must be blocking power to the xhci when the cpu is saving power...?
I believe that USB autosuspend is the culprit here. I'm seeing this problem on Fedora Linux as well, so I suspect it's an upstream bug. For those of you who are having this problem: please try disabling USB autosuspend on all USB devices, by running the following command as root: $ for F in /sys/bus/usb/devices/*/power/control; do echo on >"${F}"; done You can then verify that the power control status for all devices is "on", not "auto". E.g.: $ grep . /sys/bus/usb/devices/*/power/control /sys/bus/usb/devices/1-1/power/control:on /sys/bus/usb/devices/1-2/power/control:on /sys/bus/usb/devices/7-1/power/control:on /sys/bus/usb/devices/7-2/power/control:on /sys/bus/usb/devices/usb1/power/control:on /sys/bus/usb/devices/usb2/power/control:on /sys/bus/usb/devices/usb3/power/control:on /sys/bus/usb/devices/usb4/power/control:on /sys/bus/usb/devices/usb5/power/control:on /sys/bus/usb/devices/usb6/power/control:on /sys/bus/usb/devices/usb7/power/control:on /sys/bus/usb/devices/usb8/power/control:on If you do this, do your USB3 ports work properly? (For me, on Fedora Linux, disabling USB autosuspend made all my USB ports work perfectly.) Note: if you've already caused the xhci_hcd driver to die, you'll need to reboot first. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1242321 Title: USB 3.0 Harddrive not recognised To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1242321/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs