[ 108.191975] ======================================================
[ 108.198157] [ INFO: possible circular locking dependency detected ]
[ 108.204430] 3.17.2 #9 Not tainted
[ 108.207748] -------------------------------------------------------
[ 108.214018] kworker/u8:1/30 is trying to acquire lock:
[ 108.219160] (&priv->conf_mutex){+.+.+.}, at: [<80442380>]
cw1200_bss_params_work+0x24/0x4c
[ 108.227593]
[ 108.227593] but task is already holding lock:
[ 108.233430] ((&priv->bss_params_work)){+.+...}, at: [<8003dd44>]
process_one_work+0x13c/0x3fc
[ 108.242111]
[ 108.242111] which lock already depends on the new lock.
[ 108.242111]
[ 108.250294]
[ 108.250294] the existing dependency chain (in reverse order) is:
[ 108.257780]
-> #2 ((&priv->bss_params_work)){+.+...}:
[ 108.263065] [<8003cf10>] flush_work+0x44/0x268
[ 108.268138] [<8003eac0>] __cancel_work_timer+0x88/0x12c
[ 108.273992] [<8003eb90>] cancel_work_sync+0x14/0x18
[ 108.279497] [<804410ac>] __cw1200_cqm_bssloss_sm+0x30/0x148
[ 108.285699] [<804438b8>] cw1200_bss_info_changed+0x23c/0xc78
[ 108.291988] [<8066c23c>]
ieee80211_bss_info_change_notify+0xa8/0x11c
[ 108.298980] [<806b12cc>] ieee80211_assoc_success+0x7cc/0xa18
[ 108.305273] [<8069cefc>] ieee80211_rx_mgmt_assoc_resp+0x13c/0x26c
[ 108.311994] [<8069d32c>] ieee80211_sta_rx_queued_mgmt+0x28c/0x5e8
[ 108.318714] [<8067ba94>] ieee80211_iface_work+0x280/0x354
[ 108.324747] [<8003ddb0>] process_one_work+0x1a8/0x3fc
[ 108.330426] [<8003e158>] worker_thread+0x118/0x4d0
[ 108.335844] [<80042fec>] kthread+0xd0/0xec
[ 108.340567] [<8000eac8>] ret_from_fork+0x14/0x2c
[ 108.345817]
-> #1 (&(&priv->bss_loss_lock)->rlock){+.+...}:
[ 108.351623] [<806b631c>] _raw_spin_lock+0x34/0x44
[ 108.356958] [<804438a4>] cw1200_bss_info_changed+0x228/0xc78
[ 108.363246] [<8066c23c>]
ieee80211_bss_info_change_notify+0xa8/0x11c
[ 108.370230] [<806b12cc>] ieee80211_assoc_success+0x7cc/0xa18
[ 108.376597] [<8069cefc>] ieee80211_rx_mgmt_assoc_resp+0x13c/0x26c
[ 108.383318] [<8069d32c>] ieee80211_sta_rx_queued_mgmt+0x28c/0x5e8
[ 108.390038] [<8067ba94>] ieee80211_iface_work+0x280/0x354
[ 108.396066] [<8003ddb0>] process_one_work+0x1a8/0x3fc
[ 108.401745] [<8003e158>] worker_thread+0x118/0x4d0
[ 108.407163] [<80042fec>] kthread+0xd0/0xec
[ 108.411885] [<8000eac8>] ret_from_fork+0x14/0x2c
[ 108.417131]
-> #0 (&priv->conf_mutex){+.+.+.}:
[ 108.421808] [<800600d8>] lock_acquire+0x68/0x7c
[ 108.426971] [<806b446c>] mutex_lock_nested+0x5c/0x3c0
[ 108.432651] [<80442380>] cw1200_bss_params_work+0x24/0x4c
[ 108.438682] [<8003ddb0>] process_one_work+0x1a8/0x3fc
[ 108.444361] [<8003e158>] worker_thread+0x118/0x4d0
[ 108.449780] [<80042fec>] kthread+0xd0/0xec
[ 108.454502] [<8000eac8>] ret_from_fork+0x14/0x2c
[ 108.459749]
[ 108.459749] other info that might help us debug this:
[ 108.459749]
[ 108.467758] Chain exists of:
&priv->conf_mutex --> &(&priv->bss_loss_lock)->rlock -->
(&priv->bss_params_work)
[ 108.478281] Possible unsafe locking scenario:
[ 108.478281]
[ 108.484204] CPU0 CPU1
[ 108.488736] ---- ----
[ 108.493268] lock((&priv->bss_params_work));
[ 108.497655] lock(&(&priv->bss_loss_lock)->rlock);
[ 108.505081] lock((&priv->bss_params_work));
[ 108.511987] lock(&priv->conf_mutex);
[ 108.515766]
[ 108.515766] *** DEADLOCK ***
[ 108.515766]
[ 108.521692] 2 locks held by kworker/u8:1/30:
[ 108.525964] #0: ("%s""cw1200_wq"){.+.+.+}, at: [<8003dd44>]
process_one_work+0x13c/0x3fc
[ 108.534308] #1: ((&priv->bss_params_work)){+.+...}, at:
[<8003dd44>] process_one_work+0x13c/0x3fc
[ 108.543433]
[ 108.543433] stack backtrace:
[ 108.547799] CPU: 2 PID: 30 Comm: kworker/u8:1 Not tainted 3.17.2 #9
[ 108.554074] Workqueue: cw1200_wq cw1200_bss_params_work
[ 108.559315] Backtrace:
[ 108.561791] [<80011dc0>] (dump_backtrace) from [<80011f60>]
(show_stack+0x18/0x1c)
[ 108.569363] r6:80b28700 r5:00000000 r4:00000000 r3:be1d3a80
[ 108.575094] [<80011f48>] (show_stack) from [<806af960>]
(dump_stack+0x80/0x9c)
[ 108.582325] [<806af8e0>] (dump_stack) from [<806ad704>]
(print_circular_bug+0x284/0x2dc)
[ 108.590417] r5:80b28a30 r4:80b26610
[ 108.594032] [<806ad480>] (print_circular_bug) from [<8005f864>]
(__lock_acquire+0x19c8/0x1d0c)
[ 108.602645] r10:00000110 r9:be1d3f08 r8:80b28a30 r7:00000000
r6:811ba594 r5:be1d3ef0
[ 108.610555] r4:be1d3a80 r3:be1d3ef0
[ 108.614168] [<8005de9c>] (__lock_acquire) from [<800600d8>]
(lock_acquire+0x68/0x7c)
[ 108.621914] r10:be210000 r9:be1d3a80 r8:be210000 r7:00000000
r6:60000013 r5:be210000
[ 108.629826] r4:00000000
[ 108.632384] [<80060070>] (lock_acquire) from [<806b446c>]
(mutex_lock_nested+0x5c/0x3c0)
[ 108.640477] r7:00000000- r6:8116af54 r5:80442380 r4:bd6895ac
[ 108.646294] [<806b4410>] (mutex_lock_nested) from [<80442380>]
(cw1200_bss_params_work+0x24/0x4c)
[ 108.655168] r10:00000000 r9:00000001 r8:be210000 r7:bd42bd00
r6:bd689560 r5:bd6895ac
[ 108.663078] r4:bd68a490
[ 108.665637] [<8044235c>] (cw1200_bss_params_work) from [<8003ddb0>]
(process_one_work+0x1a8/0x3fc)
[ 108.674597] r6:be011c00 r5:bd68a490 r4:be1f3880 r3:8044235c
[ 108.680328] [<8003dc08>] (process_one_work) from [<8003e158>]
(worker_thread+0x118/0x4d0)
[ 108.688508] r10:00000088 r9:be011c00 r8:be1f3898 r7:be011c30
r6:be210000 r5:be011c00
[ 108.696417] r4:be1f3880
[ 108.698973] [<8003e040>] (worker_thread) from [<80042fec>]
(kthread+0xd0/0xec)
[ 108.706198] r10:00000000 r9:00000000 r8:00000000 r7:8003e040
r6:be1f3880 r5:be1f5100
[ 108.714107] r4:00000000
[ 108.716665] [<80042f1c>] (kthread) from [<8000eac8>]
(ret_from_fork+0x14/0x2c)
[ 108.723889] r7:00000000 r6:00000000 r5:80042f1c r4:be1f5100
--
Jonathan Bagg
Embedded Systems Developer
NAD Electronics | Lenbrook Industries Limited
633 Granite Court, Pickering, Ontario, Canada L1W 3K1 | 905-831-0799 ext 4478 | http://www.nadelectronics.com