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Message-ID: <4A1A9D1D.2050301@hartkopp.net>
Date: Mon, 25 May 2009 15:29:01 +0200
From: Oliver Hartkopp <oliver@hartkopp.net>
MIME-Version: 1.0
To: linux-bluetooth@vger.kernel.org
Subject: possible recursive locking in 2.6.30-rc6
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Sender: linux-bluetooth-owner@vger.kernel.org
List-ID: <linux-bluetooth.vger.kernel.org>

Hi all,

i'm sometimes working with BT DUN with a Nokia 6210 Navigator.

Last weekend anything must gone wrong, so my mobile was not able to create a
ppp link with DUN this morning. After updating the driver and BT-chip firmware
of my Dell 830 laptop and several pairing attempts i was able to kick it to
work again ... :-]

And i needed to move the channel from '5' to '3' in /etc/bluetooth/rfcomm.conf
- i assume the Nokia Windows Software re-configured this in the process of
re-installing their SW when updating the Windows drivers ... don't know.

In the meantime (when the paring or anything else was broken) i discovered
this kernel message about a locking issue.

Is this a known problem?

Regards,
Oliver

ps. Please CC me as i did not subcribe the list. Tnx

=============================================
[ INFO: possible recursive locking detected ]
2.6.30-rc6-02911-gbb803cf #16
---------------------------------------------
bluetooth/2518 is trying to acquire lock:
 (bluetooth){+.+.+.}, at: [<c0130c14>] flush_work+0x28/0xb0

but task is already holding lock:
 (bluetooth){+.+.+.}, at: [<c0130424>] worker_thread+0x149/0x25e

other info that might help us debug this:
2 locks held by bluetooth/2518:
 #0:  (bluetooth){+.+.+.}, at: [<c0130424>] worker_thread+0x149/0x25e
 #1:  (&conn->work_del){+.+...}, at: [<c0130424>] worker_thread+0x149/0x25e

stack backtrace:
Pid: 2518, comm: bluetooth Not tainted 2.6.30-rc6-02911-gbb803cf #16
Call Trace:
 [<c03d64d9>] ? printk+0xf/0x11
 [<c0140d96>] __lock_acquire+0x7ce/0xb1b
 [<c0141173>] lock_acquire+0x90/0xad
 [<c0130c14>] ? flush_work+0x28/0xb0
 [<c0130c2e>] flush_work+0x42/0xb0
 [<c0130c14>] ? flush_work+0x28/0xb0
 [<f8b84966>] del_conn+0x1c/0x84 [bluetooth]
 [<c0130469>] worker_thread+0x18e/0x25e
 [<c0130424>] ? worker_thread+0x149/0x25e
 [<f8b8494a>] ? del_conn+0x0/0x84 [bluetooth]
 [<c0133843>] ? autoremove_wake_function+0x0/0x33
 [<c01302db>] ? worker_thread+0x0/0x25e
 [<c013355a>] kthread+0x45/0x6b
 [<c0133515>] ? kthread+0x0/0x6b
 [<c01034a7>] kernel_thread_helper+0x7/0x10