Lockdep warning reported by Oliver Hartkopp ============================================= [ INFO: possible recursive locking detected ] 2.6.30-rc6-02911-gbb803cf #16 --------------------------------------------- bluetooth/2518 is trying to acquire lock: (bluetooth){+.+.+.}, at: [] flush_work+0x28/0xb0 but task is already holding lock: (bluetooth){+.+.+.}, at: [] worker_thread+0x149/0x25e other info that might help us debug this: 2 locks held by bluetooth/2518: #0: (bluetooth){+.+.+.}, at: [] worker_thread+0x149/0x25e #1: (&conn->work_del){+.+...}, at: [] worker_thread+0x149/0x25e stack backtrace: Pid: 2518, comm: bluetooth Not tainted 2.6.30-rc6-02911-gbb803cf #16 Call Trace: [] ? printk+0xf/0x11 [] __lock_acquire+0x7ce/0xb1b [] lock_acquire+0x90/0xad [] ? flush_work+0x28/0xb0 [] flush_work+0x42/0xb0 [] ? flush_work+0x28/0xb0 [] del_conn+0x1c/0x84 [bluetooth] [] worker_thread+0x18e/0x25e [] ? worker_thread+0x149/0x25e [] ? del_conn+0x0/0x84 [bluetooth] [] ? autoremove_wake_function+0x0/0x33 [] ? worker_thread+0x0/0x25e [] kthread+0x45/0x6b [] ? kthread+0x0/0x6b [] kernel_thread_helper+0x7/0x10 bluetoothd is a single thread workqueue, so work functions will execute in order. Just remove the flush_work handling in hci_sysfs.c Signed-off-by: Dave Young Reported-by: Oliver Hartkopp --- net/bluetooth/hci_sysfs.c | 6 ------ 1 file changed, 6 deletions(-) --- linux-2.6.orig/net/bluetooth/hci_sysfs.c 2009-05-16 17:18:10.000000000 +0800 +++ linux-2.6/net/bluetooth/hci_sysfs.c 2009-05-27 08:44:35.000000000 +0800 @@ -90,9 +90,6 @@ struct hci_conn *conn = container_of(work, struct hci_conn, work_add); struct hci_dev *hdev = conn->hdev; - /* ensure previous del is complete */ - flush_work(&conn->work_del); - dev_set_name(&conn->dev, "%s:%d", hdev->name, conn->handle); if (device_add(&conn->dev) < 0) { @@ -118,9 +115,6 @@ struct hci_conn *conn = container_of(work, struct hci_conn, work_del); struct hci_dev *hdev = conn->hdev; - /* ensure previous add is complete */ - flush_work(&conn->work_add); - if (!device_is_registered(&conn->dev)) return;