[ 328.121951] =======================================================
[ 328.122169] [ INFO: possible circular locking dependency detected ]
[ 328.122339] 2.6.30-rc5-wl-23310-ge0995c7-dirty #54
[ 328.122468] -------------------------------------------------------
[ 328.122636] pm-hibernate/7289 is trying to acquire lock:
[ 328.122779] (&(&ar->tx_status_janitor)->work){+.+...}, at: [<c00000000007eb14>] .wait_on_work+0x3c/0x194
[ 328.123058]
[ 328.123059] but task is already holding lock:
[ 328.123216] (&ar->mutex){+.+...}, at: [<d0000000015c29a4>] .ar9170_op_stop+0x60/0x120 [ar9170usb]
[ 328.123482]
[ 328.123482] which lock already depends on the new lock.
[ 328.123484]
[ 328.123702]
[ 328.123703] the existing dependency chain (in reverse order) is:
[ 328.123903]
[ 328.123904] -> #1 (&ar->mutex){+.+...}:
[ 328.124066] [<c00000000009ee40>] .check_prev_add+0x3d4/0x5f8
[ 328.124242] [<c00000000009f7b0>] .validate_chain+0x74c/0x930
[ 328.128871] [<c0000000000a01a0>] .__lock_acquire+0x80c/0x8f4
[ 328.133531] [<c0000000000a03d4>] .lock_acquire+0x14c/0x19c
[ 328.138139] [<c0000000004cb0f0>] .mutex_lock_nested+0xa8/0x504
[ 328.142769] [<d0000000015c414c>] .ar9170_tx_status_janitor+0x58/0x114 [ar9170usb]
[ 328.156599] -> #0 (&(&ar->tx_status_janitor)->work){+.+...}:
[ 328.156604] [<c00000000009eb2c>] .check_prev_add+0xc0/0x5f8
[ 328.156609] [<c00000000009f7b0>] .validate_chain+0x74c/0x930
[ 328.156614] [<c0000000000a01a0>] .__lock_acquire+0x80c/0x8f4
[ 328.156618] [<c0000000000a03d4>] .lock_acquire+0x14c/0x19c
[ 328.156623] [<c00000000007eb54>] .wait_on_work+0x7c/0x194
[ 328.156627] [<c00000000007ed50>] .__cancel_work_timer+0xe4/0x164
[ 328.156632] [<c00000000007ee00>] .cancel_delayed_work_sync+0x30/0x48
[ 328.156636] [<d0000000015c29b0>] .ar9170_op_stop+0x6c/0x120 [ar9170usb]
Don't cancel a work under a lock that it needs!
johannes
On Fri, 2009-05-15 at 13:18 +0200, Christian Lamparter wrote:
> > Don't cancel a work under a lock that it needs!
> >
> > johannes
> >
> do you have the module this time?
Yes, why? The bug is trivial:
mutex_lock(&ar->mutex);
cancel_delayed_work_sync(&ar->tx_status_janitor);
cancel_work_sync(&ar->filter_config_work);
cancel_work_sync(&ar->beacon_work);
vs.
static void ar9170_tx_status_janitor(struct work_struct *work)
{
...
mutex_lock(&ar->mutex);
johannes
On Friday 15 May 2009 12:50:42 Johannes Berg wrote:
> [ 328.121951] =======================================================
> [ 328.122169] [ INFO: possible circular locking dependency detected ]
> [ 328.122339] 2.6.30-rc5-wl-23310-ge0995c7-dirty #54
> [ 328.122468] -------------------------------------------------------
> [ 328.122636] pm-hibernate/7289 is trying to acquire lock:
> [ 328.122779] (&(&ar->tx_status_janitor)->work){+.+...}, at: [<c00000000007eb14>] .wait_on_work+0x3c/0x194
> [ 328.123058]
> [ 328.123059] but task is already holding lock:
> [ 328.123216] (&ar->mutex){+.+...}, at: [<d0000000015c29a4>] .ar9170_op_stop+0x60/0x120 [ar9170usb]
> [ 328.123482]
> [ 328.123482] which lock already depends on the new lock.
> [ 328.123484]
> [ 328.123702]
> [ 328.123703] the existing dependency chain (in reverse order) is:
> [ 328.123903]
> [ 328.123904] -> #1 (&ar->mutex){+.+...}:
> [ 328.124066] [<c00000000009ee40>] .check_prev_add+0x3d4/0x5f8
> [ 328.124242] [<c00000000009f7b0>] .validate_chain+0x74c/0x930
> [ 328.128871] [<c0000000000a01a0>] .__lock_acquire+0x80c/0x8f4
> [ 328.133531] [<c0000000000a03d4>] .lock_acquire+0x14c/0x19c
> [ 328.138139] [<c0000000004cb0f0>] .mutex_lock_nested+0xa8/0x504
> [ 328.142769] [<d0000000015c414c>] .ar9170_tx_status_janitor+0x58/0x114 [ar9170usb]
>
>
> [ 328.156599] -> #0 (&(&ar->tx_status_janitor)->work){+.+...}:
> [ 328.156604] [<c00000000009eb2c>] .check_prev_add+0xc0/0x5f8
> [ 328.156609] [<c00000000009f7b0>] .validate_chain+0x74c/0x930
> [ 328.156614] [<c0000000000a01a0>] .__lock_acquire+0x80c/0x8f4
> [ 328.156618] [<c0000000000a03d4>] .lock_acquire+0x14c/0x19c
> [ 328.156623] [<c00000000007eb54>] .wait_on_work+0x7c/0x194
> [ 328.156627] [<c00000000007ed50>] .__cancel_work_timer+0xe4/0x164
> [ 328.156632] [<c00000000007ee00>] .cancel_delayed_work_sync+0x30/0x48
> [ 328.156636] [<d0000000015c29b0>] .ar9170_op_stop+0x6c/0x120 [ar9170usb]
>
> Don't cancel a work under a lock that it needs!
>
> johannes
>
do you have the module this time?
Regards,
Chr