Open bug in Launchpad.net: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/790995 [ 482.320114] Call Trace: [ 482.320128] [<ffffffff815c140d>] schedule_timeout+0x26d/0x2e0 [ 482.320138] [<ffffffff815c0ec9>] wait_for_common+0xd9/0x180 [ 482.320147] [<ffffffff8105f5f0>] ? default_wake_function+0x0/0x20 [ 482.320154] [<ffffffff815c104d>] wait_for_completion+0x1d/0x20 [ 482.320162] [<ffffffff81087802>] kthread_stop+0x42/0xf0 [ 482.320173] [<ffffffffa031a5fe>] release_everything+0x2e/0xb0 [usb_storage] [ 482.320184] [<ffffffffa031b4ca>] usb_stor_disconnect+0x2a/0x40 [usb_storage] [ 482.320193] [<ffffffff8143e0aa>] usb_unbind_interface+0x5a/0x1a0 [ 482.320202] [<ffffffff813ba835>] __device_release_driver+0x75/0xe0 [ 482.320209] [<ffffffff813ba8cd>] device_release_driver+0x2d/0x40 [ 482.320216] [<ffffffff813ba37b>] bus_remove_device+0x7b/0xa0 [ 482.320223] [<ffffffff813b7617>] device_del+0x127/0x1b0 [ 482.320231] [<ffffffff8143be64>] usb_disable_device+0x74/0x130 [ 482.320238] [<ffffffff81434f25>] usb_disconnect+0x95/0x130 [ 482.320245] [<ffffffff8143a508>] ? usb_init_urb+0x28/0x40 [ 482.320252] [<ffffffff81435cdd>] hub_port_connect_change+0x9d/0x930 [ 482.320260] [<ffffffff814368b2>] hub_events+0x342/0x4e0 [ 482.320267] [<ffffffff81436a85>] hub_thread+0x35/0x180 [ 482.320274] [<ffffffff81087f00>] ? autoremove_wake_function+0x0/0x40 [ 482.320281] [<ffffffff81436a50>] ? hub_thread+0x0/0x180 [ 482.320287] [<ffffffff810877b6>] kthread+0x96/0xa0 [ 482.320294] [<ffffffff8100ce24>] kernel_thread_helper+0x4/0x10 [ 482.320301] [<ffffffff81087720>] ? kthread+0x0/0xa0 [ 482.320307] [<ffffffff8100ce20>] ? kernel_thread_helper+0x0/0x10 [ 482.320347] INFO: task usb-storage:2230 blocked for more than 120 seconds. [ 482.320352] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 482.320357] usb-storage D 0000000000000000 0 2230 2 0x00000000 [ 482.320365] ffff880031c6db00 0000000000000046 ffff880031c6dfd8 ffff880031c6c000 [ 482.320372] 0000000000013d00 ffff880036f1df38 ffff880031c6dfd8 0000000000013d00 [ 482.320380] ffff8800370f0000 ffff880036f1db80 ffff88003fc13d00 7fffffffffffffff [ 482.320387] Call Trace: [ 482.320395] [<ffffffff815c140d>] schedule_timeout+0x26d/0x2e0 [ 482.320402] [<ffffffff8144d4e6>] ? ehci_qtd_alloc.clone.58+0x16/0x60 [ 482.320410] [<ffffffff815c304e>] ? _raw_spin_lock+0xe/0x20 [ 482.320417] [<ffffffff81437a0c>] ? usb_hcd_link_urb_to_ep+0x8c/0xc0 [ 482.320425] [<ffffffff815c0ec9>] wait_for_common+0xd9/0x180 [ 482.320431] [<ffffffff8105f5f0>] ? default_wake_function+0x0/0x20 [ 482.320439] [<ffffffff81439296>] ? usb_hcd_submit_urb+0x76/0x150 [ 482.320446] [<ffffffff815c104d>] wait_for_completion+0x1d/0x20 [ 482.320453] [<ffffffff8143b8e0>] usb_sg_wait+0x130/0x1d0 [ 482.320459] [<ffffffff8105f5f0>] ? default_wake_function+0x0/0x20 [ 482.320469] [<ffffffffa031942f>] usb_stor_bulk_transfer_sglist+0xaf/0x110 [usb_storage] [ 482.320479] [<ffffffffa03194b5>] usb_stor_bulk_srb+0x25/0x40 [usb_storage] [ 482.320492] [<ffffffffa031969b>] usb_stor_Bulk_transport+0x11b/0x320 [usb_storage] [ 482.320502] [<ffffffffa031a07b>] usb_stor_invoke_transport+0x3b/0x440 [usb_storage] [ 482.320509] [<ffffffff815c31a5>] ? _raw_spin_lock_irq+0x15/0x20 [ 482.320516] [<ffffffff815c0f2f>] ? wait_for_common+0x13f/0x180 [ 482.320522] [<ffffffff8105f625>] ? wake_up_process+0x15/0x20 [ 482.320529] [<ffffffff8105f5f0>] ? default_wake_function+0x0/0x20 [ 482.320538] [<ffffffffa0318f7e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage] [ 482.320547] [<ffffffffa031b2c7>] usb_stor_control_thread+0x177/0x290 [usb_storage] [ 482.320558] [<ffffffffa031b150>] ? usb_stor_control_thread+0x0/0x290 [usb_storage] [ 482.320565] [<ffffffff810877b6>] kthread+0x96/0xa0 [ 482.320572] [<ffffffff8100ce24>] kernel_thread_helper+0x4/0x10 [ 482.320578] [<ffffffff81087720>] ? kthread+0x0/0xa0 [ 482.320585] [<ffffffff8100ce20>] ? kernel_thread_helper+0x0/0x10
All USB bugs should be sent to the linux-usb@vger.kernel.org mailing list, and not entered into bugzilla. Please bring this issue up there, if it is still a problem in the latest kernel release.