BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 0 PID: 1174 Comm: kworker/u5:0 Not tainted 5.1.0-rc4+ #63 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci1 hci_power_on Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 add_chain_cache kernel/locking/lockdep.c:2591 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:2665 [inline] validate_chain kernel/locking/lockdep.c:2685 [inline] __lock_acquire.cold+0x250/0x50d kernel/locking/lockdep.c:3701 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 hci_dev_do_close+0x317/0xf20 net/bluetooth/hci_core.c:1696 hci_power_on+0x1d2/0x580 net/bluetooth/hci_core.c:2191 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352