Ubuntu 15.10 - USB Bluetooth not working

Question

I have looked at some other answers already, none of them seemed applicable or fixed anything.

I have USB Bluetooth on 15.10. It used to work fine. I went to pair my headphones today and noticed I couldn't turn Bluetooth on.

Service Status

$ sudo systemctl status bluetooth -l

bluetooth.service - Bluetooth service
   Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Sun 2016-03-20 23:09:56 EDT; 3min 8s ago
     Docs: man:bluetoothd(8)
  Process: 1847 ExecStart=/usr/lib/bluetooth/bluetoothd (code=exited, status=203/EXEC)
 Main PID: 1847 (code=exited, status=203/EXEC)

Mar 20 23:09:56 brian-htpc systemd[1]: Starting Bluetooth service...
Mar 20 23:09:56 brian-htpc systemd[1]: bluetooth.service: Main process exited, code=exited, status=203/EXEC
Mar 20 23:09:56 brian-htpc systemd[1]: Failed to start Bluetooth service.
Mar 20 23:09:56 brian-htpc systemd[1]: bluetooth.service: Unit entered failed state.
Mar 20 23:09:56 brian-htpc systemd[1]: bluetooth.service: Failed with result 'exit-code'.

lsusb

$ lsusb 
Bus 002 Device 003: ID 0a5c:21e8 Broadcom Corp. BCM20702A0 Bluetooth 4.0

rfkill

$ rfkill list
0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no

dmesg

$ sudo dmesg | grep -i bluetooth
[    3.200940] Bluetooth: Core ver 2.20
[    3.200957] Bluetooth: HCI device and connection manager initialized
[    3.200963] Bluetooth: HCI socket layer initialized
[    3.200966] Bluetooth: L2CAP socket layer initialized
[    3.200973] Bluetooth: SCO socket layer initialized
[    3.220752] Bluetooth: hci0: BCM: chip id 63
[    3.223753] Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
[    3.369865] bluetooth hci0: Direct firmware load for brcm/BCM20702A1-0a5c-21e8.hcd failed with error -2
[    3.369875] Bluetooth: hci0: BCM: Patch brcm/BCM20702A1-0a5c-21e8.hcd not found

So it seems the driver or firmware for it is missing for some reason. How do I reinstall it? Is there an apt package that takes care of this?

I have tried find/locate on BCM20702A1-0a5c-21e8.hcd and wildcard variations to see if maybe it was just in the wrong place, and that does not seem to be the case - I believe it was deleted at some point, somehow.

UPDATES

As per P.H. Lin and Jeremy31's comments:

• Installing the firmware from the other thread did not fix my problem, and lsusb no longer detected a BT unit. hciconfig -a did not return any output.
• I removed the firmware file (*.hcd) rebooted and my BT unit appeared again on lbusb, with the result of sudo hciconfig -a being:

$ sudo hciconfig -a

hci0:   Type: BR/EDR  Bus: USB
    BD Address: 5C:F3:70:77:02:F7  ACL MTU: 1021:8  SCO MTU: 64:1
    UP RUNNING 
    RX bytes:616 acl:0 sco:0 events:34 errors:0
    TX bytes:380 acl:0 sco:0 commands:34 errors:0
    Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87
    Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
    Link policy: RSWITCH SNIFF 
    Link mode: SLAVE ACCEPT 
    Name: 'BCM20702A'
    Class: 0x000000
    Service Classes: Unspecified
    Device Class: Miscellaneous, 
    HCI Version: 4.0 (0x6)  Revision: 0x1000
    LMP Version: 4.0 (0x6)  Subversion: 0x220e
    Manufacturer: Broadcom Corporation (15)

However the unit still does not "work" so I am back where I started it would seem.

Answer 1

If someone else stumbles upon this, I had/have a similar problem. For whatever reason, on my system

/usr/lib/bluetooth/bluetoothd

is not executable, and thus it obviously fails to start.

So,

sudo chmod a+x /usr/lib/bluetooth/bluetoothd

fixes the problem, at least until the next reboot. Reinstalling bluex fixes it as well - though I have not rebooted yet, so I don't know if it will survive the reboot.

Answer 2

I have fixed my own issue by simply reinstall the BT stack (bluez) via apt.

sudo apt-get install --reinstall bluez

So there you have it - if your BT device is detected and seems to be working properly but just isn't showing up, try reinstalling the bluetooth stack.