That same lock debug deadlock is still there (maybe ~4 times I report it
during 2 years). Is that possible to fix easily at all?
Antti
joulu 18 17:56:37 localhost.localdomain kernel: usb 2-2: USB disconnect,
device number 2
joulu 18 17:56:37 localhost.localdomain kernel: em28174 #0:
disconnecting em28174 #0 video
joulu 18 17:56:37 localhost.localdomain kernel: joulu 18 17:56:37
localhost.localdomain kernel:
======================================================
joulu 18 17:56:37 localhost.localdomain kernel: [ INFO: possible
circular locking dependency detected ]
joulu 18 17:56:37 localhost.localdomain kernel: 3.13.0-rc1+ #77 Tainted:
G C O
joulu 18 17:56:37 localhost.localdomain kernel:
-------------------------------------------------------
joulu 18 17:56:37 localhost.localdomain kernel: khubd/34 is trying to
acquire lock:
joulu 18 17:56:37 localhost.localdomain kernel:
(em28xx_devlist_mutex){+.+.+.}, at: [<ffffffffa06edd0d>]
em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
but task is already
holding lock:
joulu 18 17:56:37 localhost.localdomain kernel: (&dev->lock){+.+.+.},
at: [<ffffffffa06eb689>] em28xx_usb_disconnect+0x99/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
which lock already
depends on the new lock.
joulu 18 17:56:37 localhost.localdomain kernel:
the existing dependency
chain (in reverse order) is:
joulu 18 17:56:37 localhost.localdomain kernel:
-> #1 (&dev->lock){+.+.+.}:
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810bb386>] __lock_acquire+0x3d6/0xc40
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810bbca0>] lock_acquire+0xb0/0x150
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff816be5b7>] mutex_lock_nested+0x77/0x3d0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffffa077b6d5>] em28xx_dvb_init+0x85/0x1b44 [em28xx_dvb]
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffffa06eb908>] em28xx_register_extension+0x58/0xa0 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffffa0783010>] 0xffffffffa0783010
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff8100214a>] do_one_initcall+0xfa/0x1b0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810eec72>] load_module+0x13c2/0x1a80
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810ef4c6>] SyS_finit_module+0x86/0xb0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff816ca729>] system_call_fastpath+0x16/0x1b
joulu 18 17:56:37 localhost.localdomain kernel:
-> #0
(em28xx_devlist_mutex){+.+.+.}:
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810b96b7>] validate_chain.isra.36+0x10d7/0x1130
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810bb386>] __lock_acquire+0x3d6/0xc40
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff810bbca0>] lock_acquire+0xb0/0x150
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff816be5b7>] mutex_lock_nested+0x77/0x3d0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffffa06edd0d>] em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffffa06eb6a3>] em28xx_usb_disconnect+0xb3/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814b7c87>] usb_unbind_interface+0x67/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814378ff>] __device_release_driver+0x7f/0xf0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff81437995>] device_release_driver+0x25/0x40
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814371fc>] bus_remove_device+0x11c/0x1a0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff81433c26>] device_del+0x136/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814b5660>] usb_disable_device+0xb0/0x290
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814aa5f5>] usb_disconnect+0xb5/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814acfe6>] hub_port_connect_change+0xd6/0xad0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814adcf3>] hub_events+0x313/0x9b0
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff814ae3c5>] hub_thread+0x35/0x190
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff8109044f>] kthread+0xff/0x120
joulu 18 17:56:37 localhost.localdomain kernel:
[<ffffffff816ca67c>] ret_from_fork+0x7c/0xb0
joulu 18 17:56:37 localhost.localdomain kernel:
other info that might
help us debug this:
joulu 18 17:56:37 localhost.localdomain kernel: Possible unsafe locking
scenario:
joulu 18 17:56:37 localhost.localdomain kernel: CPU0
CPU1
joulu 18 17:56:37 localhost.localdomain kernel: ----
----
joulu 18 17:56:37 localhost.localdomain kernel: lock(&dev->lock);
joulu 18 17:56:37 localhost.localdomain kernel:
lock(em28xx_devlist_mutex);
joulu 18 17:56:37 localhost.localdomain kernel:
lock(&dev->lock);
joulu 18 17:56:37 localhost.localdomain kernel:
lock(em28xx_devlist_mutex);
joulu 18 17:56:37 localhost.localdomain kernel:
*** DEADLOCK ***
joulu 18 17:56:37 localhost.localdomain kernel: 4 locks held by khubd/34:
joulu 18 17:56:37 localhost.localdomain kernel: #0:
(&__lockdep_no_validate__){......}, at: [<ffffffff814ada94>]
hub_events+0xb4/0x9b0
joulu 18 17:56:37 localhost.localdomain kernel: #1:
(&__lockdep_no_validate__){......}, at: [<ffffffff814aa5a6>]
usb_disconnect+0x66/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel: #2:
(&__lockdep_no_validate__){......}, at: [<ffffffff8143798d>]
device_release_driver+0x1d/0x40
joulu 18 17:56:37 localhost.localdomain kernel: #3:
(&dev->lock){+.+.+.}, at: [<ffffffffa06eb689>]
em28xx_usb_disconnect+0x99/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel:
stack backtrace:
joulu 18 17:56:37 localhost.localdomain kernel: CPU: 3 PID: 34 Comm:
khubd Tainted: G C O 3.13.0-rc1+ #77
joulu 18 17:56:37 localhost.localdomain kernel: Hardware name: System
manufacturer System Product Name/M5A78L-M/USB3, BIOS 1503 11/14/2012
joulu 18 17:56:37 localhost.localdomain kernel: ffffffff824f59f0
ffff88030dbb98e8 ffffffff816b8da9 ffffffff824f59f0
joulu 18 17:56:37 localhost.localdomain kernel: ffff88030dbb9928
ffffffff816b2c9b ffff88030dbb9960 0000000000000003
joulu 18 17:56:37 localhost.localdomain kernel: ffff88030da1afd0
0000000000000004 ffff88030da1a8a0 ffff88030da1afd0
joulu 18 17:56:37 localhost.localdomain kernel: Call Trace:
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff816b8da9>]
dump_stack+0x4d/0x66
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff816b2c9b>]
print_circular_bug+0x200/0x20e
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810b96b7>]
validate_chain.isra.36+0x10d7/0x1130
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff8101c413>] ?
native_sched_clock+0x13/0x80
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810bb386>]
__lock_acquire+0x3d6/0xc40
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810bb3a7>] ?
__lock_acquire+0x3f7/0xc40
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810bbca0>]
lock_acquire+0xb0/0x150
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06edd0d>] ?
em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff816be5b7>]
mutex_lock_nested+0x77/0x3d0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06edd0d>] ?
em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810b9e6d>] ?
trace_hardirqs_on+0xd/0x10
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06edd0d>] ?
em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06eb689>] ?
em28xx_usb_disconnect+0x99/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06eb689>] ?
em28xx_usb_disconnect+0x99/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06edd0d>]
em28xx_close_extension+0x1d/0x70 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffffa06eb6a3>]
em28xx_usb_disconnect+0xb3/0x140 [em28xx]
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814b7c87>]
usb_unbind_interface+0x67/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814378ff>]
__device_release_driver+0x7f/0xf0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff81437995>]
device_release_driver+0x25/0x40
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814371fc>]
bus_remove_device+0x11c/0x1a0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff81433c26>]
device_del+0x136/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814b5660>]
usb_disable_device+0xb0/0x290
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814aa5f5>]
usb_disconnect+0xb5/0x1d0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814acfe6>]
hub_port_connect_change+0xd6/0xad0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814b40a4>] ?
usb_control_msg+0xd4/0x110
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814adcf3>]
hub_events+0x313/0x9b0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814ae3c5>]
hub_thread+0x35/0x190
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff810b12d0>] ?
abort_exclusive_wait+0xb0/0xb0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff814ae390>] ?
hub_events+0x9b0/0x9b0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff8109044f>]
kthread+0xff/0x120
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff81090350>] ?
kthread_create_on_node+0x250/0x250
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff816ca67c>]
ret_from_fork+0x7c/0xb0
joulu 18 17:56:37 localhost.localdomain kernel: [<ffffffff81090350>] ?
kthread_create_on_node+0x250/0x250
joulu 18 17:56:37 localhost.localdomain kernel: tda18271 6-0060:
destroying instance
joulu 18 17:56:37 localhost.localdomain kernel: rc_unregister_device:
Freed keycode table
joulu 18 17:56:37 localhost.localdomain kernel: em28174 #0: V4L2 device
video0 deregistered
joulu 18 17:56:37 localhost.localdomain kernel: i2c i2c-6: adapter
[em28174 #0] unregistered
joulu 18 17:56:37 localhost.localdomain kernel: i2c i2c-5: adapter
[em28174 #0] unregistered
joulu 18 17:56:37 localhost.localdomain colord[603]: device removed:
sysfs-PCTV_Systems-PCTV_290e
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