After we made debugobjects working again, we got the following:

WARNING: at lib/debugobjects.c:262 debug_print_object+0x8e/0xb0()
Hardware name: System Product Name
ODEBUG: free active (active state 0) object type: timer_list hint: hci_cmd_timer+0x0/0x60
Pid: 2125, comm: dmsetup Tainted: G        W   2.6.38-06707-gc62b3898 #110375
Call Trace:
 [<ffffffff8104700a>] warn_slowpath_common+0x7a/0xb0
 [<ffffffff810470b6>] warn_slowpath_fmt+0x46/0x50
 [<ffffffff812d3a5e>] debug_print_object+0x8e/0xb0
 [<ffffffff81bd8810>] ? hci_cmd_timer+0x0/0x60
 [<ffffffff812d4685>] debug_check_no_obj_freed+0x125/0x230
 [<ffffffff810f1063>] ? check_object+0xb3/0x2b0
 [<ffffffff810f3630>] kfree+0x150/0x190
 [<ffffffff81be4d06>] ? bt_host_release+0x16/0x20
 [<ffffffff81be4d06>] bt_host_release+0x16/0x20
 [<ffffffff813a1907>] device_release+0x27/0xa0
 [<ffffffff812c519c>] kobject_release+0x4c/0xa0
 [<ffffffff812c5150>] ? kobject_release+0x0/0xa0
 [<ffffffff812c61f6>] kref_put+0x36/0x70
 [<ffffffff812c4d37>] kobject_put+0x27/0x60
 [<ffffffff813a21f7>] put_device+0x17/0x20
 [<ffffffff81bda4f9>] hci_free_dev+0x29/0x30
 [<ffffffff81928be6>] vhci_release+0x36/0x70
 [<ffffffff810fb366>] fput+0xd6/0x1f0
 [<ffffffff810f8fe6>] filp_close+0x66/0x90
 [<ffffffff810f90a9>] sys_close+0x99/0xf0
 [<ffffffff81d4c96b>] system_call_fastpath+0x16/0x1b

That timer was introduced with commit 6bd32326(Bluetooth: Use
proper timer for hci command timout)

Timer seems to be running when the thing is closed. Removing the timer
unconditionally fixes the problem. And yes, it needs to be fixed
before the HCI_UP check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>