bluetooth broken: requires OS X boot

using mac mini 6.1, dual boot, but only Ubuntu 12.04 LTS used for many years.

I never had any problem using apple aluminium bluetooth keyboard

I recently upgraded to 16.04, everything was fine for about a month,

then bluetooth failed to load on start,

via search engine eventually discovered workaround, boot into OS X 64bit,
no need to login or anything just pick option and reboot.

then bluetooth just works again.

not clear what stops it working, I had updated today, and was using keyboard/mouse
when I discovered bluetooth logo missing from top bar....

#1001825 may be related? currently 12.04 specific

Mac mini 6.2 Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz

had been running UbuntuLTS 14.04 and using Apple Aluminium Keyboard

however after upgrade to 16.04, bluetooth is not coonecting, icon is not in top bar.

~$ dmesg | grep -i bluetooth
[ 2.797266] usb 2-1.8.1.3: Product: Broadcom Bluetooth Download Device
[167220.284394] Bluetooth: Core ver 2.21
[167220.284439] Bluetooth: HCI device and connection manager initialized
[167220.284444] Bluetooth: HCI socket layer initialized
[167220.284448] Bluetooth: L2CAP socket layer initialized
[167220.284457] Bluetooth: SCO socket layer initialized

~$ rfkill list
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
1: brcmwl-0: Wireless LAN
Soft blocked: no
Hard blocked: no

~$ hcitool dev
Devices:

~$ uname -a
Linux jay-Macmini6 4.4.0-34-generic #53-Ubuntu SMP Wed Jul 27 16:06:39 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: bluez 5.37-0ubuntu5
ProcVersionSignature: Ubuntu 4.4.0-34.53-generic 4.4.15
Uname: Linux 4.4.0-34-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Sep 20 22:16:48 2016
InstallationDate: Installed on 2014-11-26 (664 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: Apple Inc. Macmini6,2
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-34-generic.efi.signed root=UUID=480bf015-3d89-4bba-b953-1cb9e454201c ro quiet splash vt.handoff=7
SourcePackage: bluez
UpgradeStatus: Upgraded to xenial on 2016-08-06 (45 days ago)
dmi.bios.date: 09/19/2013
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MM61.88Z.0106.B04.1309191433
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-F65AE981FFA204ED
dmi.board.vendor: Apple Inc.
dmi.board.version: Macmini6,2
dmi.chassis.type: 16
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F65AE981FFA204ED
dmi.modalias: dmi:bvnAppleInc.:bvrMM61.88Z.0106.B04.1309191433:bd09/19/2013:svnAppleInc.:pnMacmini6,2:pvr1.0:rvnAppleInc.:rnMac-F65AE981FFA204ED:rvrMacmini6,2:cvnAppleInc.:ct16:cvrMac-F65AE981FFA204ED:
dmi.product.name: Macmini6,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
hciconfig:
 hci0: Type: BR/EDR Bus: USB
  BD Address: A8:8E:24:A4:2E:66 ACL MTU: 1021:8 SCO MTU: 64:1
  UP RUNNING PSCAN
  RX bytes:6039 acl:249 sco:0 events:106 errors:0
  TX bytes:3360 acl:21 sco:0 commands:67 errors:0