Comment 19 for bug 1488426

@Aditya Thanks for the clarification. I had been trying to find out if the patch had been merged.

The issue is not however fixed for me with 4.2 nor was it for lpuser in #8 who tried a number of kernels. However it an improvement as I said in #17

The following shows the problem first without BT on then with showing the problem disappearing:

:~$ uname -r
4.2.0-19-generic
pete@Helios-Ubuntu:~$ top

in, 2 users, load average: 0.71, 0.28, 0.11
Tasks: 238 total, 2 running, 236 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.8 us, 25.0 sy, 0.0 ni, 73.8 id, 0.0 wa, 0.0 hi, 0.4 si, 0.0 st
KiB Mem: 8082944 total, 1196884 used, 6886060 free, 61504 buffers
KiB Swap: 10239996 total, 0 used, 10239996 free. 542960 cached Mem

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
   50 root 20 0 0 0 0 R 71.2 0.0 0:15.14 kworker/0:1
    3 root 20 0 0 0 0 S 28.9 0.0 0:11.58 ksoftirqd/0
  729 root 20 0 294360 11812 7432 S 1.7 0.1 0:08.33 polkitd
 1182 pete 20 0 1451368 183784 60088 S 1.7 2.3 0:25.51 cinnamon
  145 root 20 0 0 0 0 S 0.3 0.0 0:00.10 kworker/u8+
  638 root 20 0 462888 19056 13656 S 0.3 0.2 0:03.32 NetworkMan+
  644 message+ 20 0 44192 5004 3480 S 0.3 0.1 0:03.83 dbus-daemon
  796 root 20 0 405348 86652 76272 S 0.3 1.1 0:07.15 Xorg
    1 root 20 0 37748 5784 3892 S 0.0 0.1 0:01.13 systemd
    2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
    4 root 20 0 0 0 0 S 0.0 0.0 0:13.54 kworker/0:0
    5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:+
    6 root 20 0 0 0 0 S 0.0 0.0 0:00.03 kworker/u8+
    7 root 20 0 0 0 0 S 0.0 0.0 0:00.39 rcu_sched
    8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
    9 root 20 0 0 0 0 S 0.0 0.0 0:00.35 rcuos/0
   10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/0
pete@Helios-Ubuntu:~$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 480M
    |__ Port 4: Dev 3, If 0, Class=Video, Driver=uvcvideo, 480M
    |__ Port 4: Dev 3, If 1, Class=Video, Driver=uvcvideo, 480M

=========== Now Switch on Bluetooth ==============
~$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 480M
    |__ Port 3: Dev 4, If 0, Class=Wireless, Driver=btusb, 12M
    |__ Port 3: Dev 4, If 1, Class=Wireless, Driver=btusb, 12M
    |__ Port 4: Dev 3, If 0, Class=Video, Driver=uvcvideo, 480M
    |__ Port 4: Dev 3, If 1, Class=Video, Driver=uvcvideo, 480M
$ top

top - 09:21:47 up 9 min, 2 users, load average: 0.79, 0.69, 0.32
Tasks: 246 total, 1 running, 245 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.1 us, 0.3 sy, 0.0 ni, 97.6 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem: 8082944 total, 1289152 used, 6793792 free, 74748 buffers
KiB Swap: 10239996 total, 0 used, 10239996 free. 569360 cached Mem

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 1182 pete 20 0 1453084 185460 60264 S 4.0 2.3 0:34.76 cinnamon
  729 root 20 0 294756 12112 7432 S 2.6 0.1 0:11.52 polkitd
  638 root 20 0 462888 17052 13676 S 1.0 0.2 0:04.52 NetworkMan+
  644 message+ 20 0 44192 5080 3480 S 1.0 0.1 0:05.15 dbus-daemon
 2150 pete 20 0 29220 3172 2592 R 0.7 0.0 0:00.06 top
  796 root 20 0 405400 87404 77020 S 0.3 1.1 0:09.59 Xorg
    1 root 20 0 119676 5812 3892 S 0.0 0.1 0:01.15 systemd
    2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
    3 root 20 0 0 0 0 S 0.0 0.0 1:03.84 ksoftirqd/0
    4 root 20 0 0 0 0 S 0.0 0.0 1:16.92 kworker/0:0
    5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:+
    6 root 20 0 0 0 0 S 0.0 0.0 0:00.03 kworker/u8+
    7 root 20 0 0 0 0 S 0.0 0.0 0:00.50 rcu_sched
    8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
    9 root 20 0 0 0 0 S 0.0 0.0 0:00.39 rcuos/0
   10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/0

I hope a solution to my problem has been found at http://linux-kernel.2935.n7.nabble.com/TESTPATCH-v2-xhci-fix-usb2-resume-timing-and-races-tc1250796.html#a1256745