USB BT dongle freezes machine

Bug #930848 reported by KeithG on 2012-02-12
This bug affects 8 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)

Bug Description

new BT dongle is very flaky. If it will pair, whenever it is used to send any data, it freezes the machine (flashing caps lock and num lock leds). The only way to get it back is to press and hold the power button. I have 2 other dongles which work fine. It announces itself as a "ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)" like the another one I have. I have been able to make it work under Win7 x64.

usb-devices reports more information:
T: Bus=04 Lev=01 Prnt=01 Port=03 Cnt=01 Dev#= 9 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0a12 ProdID=0001 Rev=19.15
C: #Ifs= 2 Cfg#= 1 Atr=c0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
I: If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb

The key is the Rev 19.15. This one does not work I have another one which reports Rev 01.34 and it works fine.

I have seen this showing up around the web. The compatibility lists all list Cambridge Silicon Radio, Ltd 0a12:0001, but not all of these devices that report this are the same, or so it appears. Don't know if it just because it is a BT 2.0 and it is incorrectly assigned a driver.

This is on Ubuntu 11.10 x64

This is with gnome-bluetooth or Bluetooth-manager

I got a freeze, I expected a connection and a file transfer

KeithG (grider-4) wrote :

The chip in the adapter is marked OVC3620. Do not know if this is helpful or not.

Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in gnome-bluetooth (Ubuntu):
status: New → Confirmed
diabolik2 (lui-palmiero) wrote :

this bug affect also me. The system freeze on attempt to pair my phone or trasfer file.
My bluetooh dongle is: "ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)"
I am on Ubuntu 11.10 x86 , kernel 3.0.0-16-generic

diabolik2 (lui-palmiero) wrote :

Many information:

Command: hciconfig -a hci0
hci0: Type: BR/EDR Bus: USB
 BD Address: 00:1F:81:00:02:50 ACL MTU: 1021:4 SCO MTU: 180:1
 RX bytes:1014 acl:0 sco:0 events:28 errors:0
 TX bytes:622 acl:0 sco:0 commands:27 errors:0
 Features: 0xff 0x3e 0x0d 0x76 0x80 0x01 0x00 0x80
 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
 Link mode: SLAVE ACCEPT
 Name: 'adnusielog4-0'
 Class: 0x4a0100
 Service Classes: Networking, Capturing, Telephony
 Device Class: Computer, Uncategorized
 HCI Version: 2.0 (0x3) Revision: 0x3
 LMP Version: 2.0 (0x3) Subversion: 0x3
 Manufacturer: Cambridge Silicon Radio (10)

Command: usb-devices
T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0002 Rev=03.00
S: Manufacturer=Linux 3.0.0-16-generic ehci_hcd
S: Product=EHCI Host Controller
S: SerialNumber=0000:00:1d.7
C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub


Joseph S (supermariolinux) wrote :

I am experiencing this same problem with this Bluetooth dongle i got from eBay.

this happens on both 11.10 and 12.04 Beta 2(i have on my netbook)

this has to be one of the most bizarre problems...

its intersting how this device is shown on
to be working apparntly.

this seems to be the last of dmesg before it froze:

[ 56.635471] Bluetooth: Core ver 2.16
[ 56.635499] NET: Registered protocol family 31
[ 56.635500] Bluetooth: HCI device and connection manager initialized
[ 56.635502] Bluetooth: HCI socket layer initialized
[ 56.635504] Bluetooth: L2CAP socket layer initialized
[ 56.635718] Bluetooth: SCO socket layer initialized

[ 119.524320] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 119.524328] Bluetooth: BNEP filters: protocol multicast
[ 119.580702] Bluetooth: RFCOMM TTY layer initialized
[ 119.580709] Bluetooth: RFCOMM socket layer initialized
[ 119.580710] Bluetooth: RFCOMM ver 1.11
[ 166.261094] do_general_protection: 60 callbacks suppressed
[ 166.261098] ica[4052] general protection ip:7f998bc156dc sp:7fff995f0e00 error:0 in[7f998bb5d000+42f000]
[ 198.650473] v4l2loopack driver version 1.0.2 loaded
[ 198.888456] init: plymouth-stop pre-start process (4328) terminated with status 1
[ 248.135230] type=1400 audit(1334247366.738:40): apparmor="DENIED" operation="open" parent=1 profile="/opt/" name="/etc/default/apport" pid=4580 comm="unity-scope-cal" requested_mask="r" denied_mask="r" fsuid=1000 ouid=0
[ 248.177522] type=1400 audit(1334247366.782:41): apparmor="DENIED" operation="open" parent=1 profile="/opt/" name="/etc/apt/apt.conf.d/" pid=4580 comm="unity-scope-cal" requested_mask="r" denied_mask="r" fsuid=1000 ouid=0

possibly a problem with unity? i will check the status with another DE.

Joseph S (supermariolinux) wrote :

it freezes in other DE's as well, it only seems to freeze when you try to transfer a file, or connect a device to it.

KeithG (grider-4) wrote :

For what it is worth, this same dongle hangs a windows 7 machine as well as a Mac.

Experienced a Kernel Panic on a USB BT Dongle. Now and then Caps lock blinks, or XOrg session starts over. Kernel panic. And in some other time I can connect my BT mouse OK. What is the root cause of that issue.

Vladimir Donkov (flatko) wrote :

Same issue in 12.04 - every time I try to pair, a kernel panic occurs. I haven't sent a single byte successfully. The system freezes at the moment of pairing.

Under 10.04 it says that bluetooth is disabled and there's no way to enable it.

Jelle De Loecker (skerit) wrote :

Same problem on Ubuntu 12.10, kernel 3.5.0-18-generic.
As soon as I try to create a connection the system freezes.

Sometimes it seems as only the usb bus is frozen. I can't toggle my keyboard num lock, move the mouse pointer, ... but the screen will still be updating.
Though mostly it just freezes the entire system.

KeithG, thank you for reporting this and helping make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect BUGNUMBER
When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at

affects: gnome-bluetooth (Ubuntu) → linux (Ubuntu)
Changed in linux (Ubuntu):
importance: Undecided → Medium
status: Confirmed → Incomplete
Launchpad Janitor (janitor) wrote :

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Changed in linux (Ubuntu):
status: Incomplete → Expired
Dietrich Müller (dieterm57) wrote :

still an issue for 12.10 with 3.5 and 3.8 kernel

Dietrich Müller, if you have a bug in Ubuntu, could you please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:

the Ubuntu Bug Control team and Ubuntu Bug Squad team article:

and Ubuntu Community article:

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report may delay your problem being addressed as quickly as possible.

Thank you for your understanding.

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