possible recursive locking: find_ref_lock() / v4l2_ctrl_add_handler()
Maybe somebody could have at that old locking warning:
[9.761427] cx88/2: cx2388x MPEG-TS Driver Manager version 0.0.9 loaded
[9.782848] cx88/0: cx2388x v4l2 driver version 0.0.9 loaded
[9.794205] input: HDA Digital PCBeep as
/devices/pci:00/:00:1b.0/input/input5
[9.879194] cx88[0]: subsystem: 0070:6906, board: Hauppauge
WinTV-HVR4000(Lite) DVB-S/S2 [card=69,autodetected], frontend(s): 1
[9.914871] input: HDA Intel Line as
/devices/pci:00/:00:1b.0/sound/card0/input6
[9.932037] cx88[0]: TV tuner type -1, Radio tuner type -1
[9.953646] input: HDA Intel Front Mic as
/devices/pci:00/:00:1b.0/sound/card0/input7
[9.981718] input: HDA Intel Rear Mic as
/devices/pci:00/:00:1b.0/sound/card0/input8
[9.996493] input: HDA Intel Line Out CLFE as
/devices/pci:00/:00:1b.0/sound/card0/input9
[ 10.003354] input: HDA Intel Line Out Surround as
/devices/pci:00/:00:1b.0/sound/card0/input10
[ 10.007987] input: HDA Intel Line Out Front as
/devices/pci:00/:00:1b.0/sound/card0/input11
[ 10.450310] tveeprom 9-0050: Hauppauge model 69100, rev B4C3, serial# 7900937
[ 10.453751] tveeprom 9-0050: MAC address is 00:0d:fe:78:8f:09
[ 10.457134] tveeprom 9-0050: tuner model is Conexant CX24118A (idx 123, type
4)
[ 10.460547] tveeprom 9-0050: TV standards ATSC/DVB Digital (eeprom 0x80)
[ 10.463936] tveeprom 9-0050: audio processor is None (idx 0)
[ 10.467320] tveeprom 9-0050: decoder processor is CX880 (idx 20)
[ 10.470648] tveeprom 9-0050: has no radio, has IR receiver, has no IR
transmitter
[ 10.474038] cx88[0]: hauppauge eeprom: model=69100
[ 10.508060] Registered IR keymap rc-hauppauge
[ 10.518107] input: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0/input12
[ 10.526485] rc0: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0
[ 10.530869] cx88[0]/2: cx2388x 8802 Driver Manager
[ 10.534533] cx88[0]/2: found at :05:05.2, rev: 5, irq: 17, latency: 32,
mmio: 0xd200
[ 10.541221] cx88[0]/0: found at :05:05.0, rev: 5, irq: 17, latency: 32,
mmio: 0xd000
[ 10.545197] IR RC5(x) protocol handler initialized
[ 10.557935]
[ 10.560012] =
[ 10.560012] [ INFO: possible recursive locking detected ]
[ 10.560012] 3.8.0-rc7-main #20 Not tainted
[ 10.560012] -
[ 10.560012] modprobe/469 is trying to acquire lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85604f6] find_ref_lock+0x1f/0x39
[videodev]
[ 10.560012]
[ 10.560012] but task is already holding lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] other info that might help us debug this:
[ 10.560012] Possible unsafe locking scenario:
[ 10.560012]
[ 10.560012]CPU0
[ 10.560012]
[ 10.560012] lock(hdl-lock);
[ 10.560012] lock(hdl-lock);
[ 10.560012]
[ 10.560012] *** DEADLOCK ***
[ 10.560012]
[ 10.560012] May be due to missing lock nesting notation
[ 10.560012]
[ 10.560012] 3 locks held by modprobe/469:
[ 10.560012] #0: (__lockdep_no_validate__){..}, at: [c03cbcfc]
__driver_attach+0x31/0x6b
[ 10.560012] #1: (__lockdep_no_validate__){..}, at: [c03cbd08]
__driver_attach+0x3d/0x6b
[ 10.560012] #2: (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] stack backtrace:
[ 10.560012] Pid: 469, comm: modprobe Not tainted 3.8.0-rc7-main #20
[ 10.560012] Call Trace:
[ 10.560012] [c01272cb] ? console_unlock+0x34b/0x374
[ 10.560012] [c015b25a] __lock_acquire+0x1314/0x138a
[ 10.560012] [c015bc94] ? mark_held_locks+0xa1/0xc8
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c015b703] lock_acquire+0xaf/0xcd
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c04f8ae0] mutex_lock_nested+0x3a/0x266
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c04f8cc8] ? mutex_lock_nested+0x222/0x266
[ 10.560012] [c04f8cf1] ? mutex_lock_nested+0x24b/0x266
[ 10.560012] [f85604f6] find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [f8560db7] handler_new_ref+0x38/0x143 [videodev]
[ 10.560012] [f856230b] v4l2_ctrl_add_handler+0x6d/0x91 [videodev]
[ 10.560012] [f85c2961] cx8800_initdev+0x329/0x673 [cx8800]
[ 10.560012] [c04fd581] ? sub_preempt_count+0x90/0x9d
[ 10.560012] [c04faa54] ? _raw_spin_unlock_irqrestore+0x44/0x5b
[ 10.560012] [c03d0acd] ? __pm_runtime_resume+0x40/0x48
[ 10.560012] [c02e6ca4] pci_device_probe+0x5f/0x96
[ 10.560012] [c03cbbe7] driver_probe_device+0x8f/0x173
[ 10.560012] [c03cbd1a] __driver_attach+0x4f/0x6b
[ 10.560012] [c03ca895] bus_for_each_dev+0x44/0x66
[ 10.560012]
Re: possible recursive locking: find_ref_lock() / v4l2_ctrl_add_handler()
On Sun February 10 2013 11:34:11 Knut Petersen wrote:
Maybe somebody could have at that old locking warning:
It's a false warning. If someone can point me to some documentation on how to
tell lockdep that it isn't a deadlock, then that would be appreciated.
Regards,
Hans
[9.761427] cx88/2: cx2388x MPEG-TS Driver Manager version 0.0.9 loaded
[9.782848] cx88/0: cx2388x v4l2 driver version 0.0.9 loaded
[9.794205] input: HDA Digital PCBeep as
/devices/pci:00/:00:1b.0/input/input5
[9.879194] cx88[0]: subsystem: 0070:6906, board: Hauppauge
WinTV-HVR4000(Lite) DVB-S/S2 [card=69,autodetected], frontend(s): 1
[9.914871] input: HDA Intel Line as
/devices/pci:00/:00:1b.0/sound/card0/input6
[9.932037] cx88[0]: TV tuner type -1, Radio tuner type -1
[9.953646] input: HDA Intel Front Mic as
/devices/pci:00/:00:1b.0/sound/card0/input7
[9.981718] input: HDA Intel Rear Mic as
/devices/pci:00/:00:1b.0/sound/card0/input8
[9.996493] input: HDA Intel Line Out CLFE as
/devices/pci:00/:00:1b.0/sound/card0/input9
[ 10.003354] input: HDA Intel Line Out Surround as
/devices/pci:00/:00:1b.0/sound/card0/input10
[ 10.007987] input: HDA Intel Line Out Front as
/devices/pci:00/:00:1b.0/sound/card0/input11
[ 10.450310] tveeprom 9-0050: Hauppauge model 69100, rev B4C3, serial#
7900937
[ 10.453751] tveeprom 9-0050: MAC address is 00:0d:fe:78:8f:09
[ 10.457134] tveeprom 9-0050: tuner model is Conexant CX24118A (idx 123,
type 4)
[ 10.460547] tveeprom 9-0050: TV standards ATSC/DVB Digital (eeprom 0x80)
[ 10.463936] tveeprom 9-0050: audio processor is None (idx 0)
[ 10.467320] tveeprom 9-0050: decoder processor is CX880 (idx 20)
[ 10.470648] tveeprom 9-0050: has no radio, has IR receiver, has no IR
transmitter
[ 10.474038] cx88[0]: hauppauge eeprom: model=69100
[ 10.508060] Registered IR keymap rc-hauppauge
[ 10.518107] input: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0/input12
[ 10.526485] rc0: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0
[ 10.530869] cx88[0]/2: cx2388x 8802 Driver Manager
[ 10.534533] cx88[0]/2: found at :05:05.2, rev: 5, irq: 17, latency:
32, mmio: 0xd200
[ 10.541221] cx88[0]/0: found at :05:05.0, rev: 5, irq: 17, latency:
32, mmio: 0xd000
[ 10.545197] IR RC5(x) protocol handler initialized
[ 10.557935]
[ 10.560012] =
[ 10.560012] [ INFO: possible recursive locking detected ]
[ 10.560012] 3.8.0-rc7-main #20 Not tainted
[ 10.560012] -
[ 10.560012] modprobe/469 is trying to acquire lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85604f6] find_ref_lock+0x1f/0x39
[videodev]
[ 10.560012]
[ 10.560012] but task is already holding lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] other info that might help us debug this:
[ 10.560012] Possible unsafe locking scenario:
[ 10.560012]
[ 10.560012]CPU0
[ 10.560012]
[ 10.560012] lock(hdl-lock);
[ 10.560012] lock(hdl-lock);
[ 10.560012]
[ 10.560012] *** DEADLOCK ***
[ 10.560012]
[ 10.560012] May be due to missing lock nesting notation
[ 10.560012]
[ 10.560012] 3 locks held by modprobe/469:
[ 10.560012] #0: (__lockdep_no_validate__){..}, at: [c03cbcfc]
__driver_attach+0x31/0x6b
[ 10.560012] #1: (__lockdep_no_validate__){..}, at: [c03cbd08]
__driver_attach+0x3d/0x6b
[ 10.560012] #2: (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] stack backtrace:
[ 10.560012] Pid: 469, comm: modprobe Not tainted 3.8.0-rc7-main #20
[ 10.560012] Call Trace:
[ 10.560012] [c01272cb] ? console_unlock+0x34b/0x374
[ 10.560012] [c015b25a] __lock_acquire+0x1314/0x138a
[ 10.560012] [c015bc94] ? mark_held_locks+0xa1/0xc8
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c015b703] lock_acquire+0xaf/0xcd
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c04f8ae0] mutex_lock_nested+0x3a/0x266
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c04f8cc8] ? mutex_lock_nested+0x222/0x266
[ 10.560012] [c04f8cf1] ? mutex_lock_nested+0x24b/0x266
[ 10.560012] [f85604f6] find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [f8560db7] handler_new_ref+0x38/0x143 [videodev]
[ 10.560012] [f856230b] v4l2_ctrl_add_handler+0x6d/0x91 [videodev]
[ 10.560012] [f85c2961] cx8800_initdev+0x329/0x673 [cx8800]
[ 10.560012] [c04fd581] ? sub_preempt_count+0x90/0x9d
[ 10.560012] [c04faa54] ?
Re: possible recursive locking: find_ref_lock() / v4l2_ctrl_add_handler()
On Sun, 2013-02-10 at 11:54 +0100, Hans Verkuil wrote:
On Sun February 10 2013 11:34:11 Knut Petersen wrote:
Maybe somebody could have at that old locking warning:
It's a false warning. If someone can point me to some documentation on how to
tell lockdep that it isn't a deadlock, then that would be appreciated.
Hi Hans,
Here you go, an old patch for you:
http://permalink.gmane.org/gmane.linux.drivers.video-input-infrastructure/27027
Be warned, if lockdep has a limit on the number of classes it can
handle, then my patch could be a problem with a large number of drivers
with v4l2_ctrl_handlers loaded. I must emphasize, that is a new lock
classes per driver instance, not per hardware device instance ... IIRC.
FYI, here's some context that led up to me making the patch:
http://www.gossamer-threads.com/lists/ivtv/devel/41525#41525
Regards,
Andy
Regards,
Hans
[9.761427] cx88/2: cx2388x MPEG-TS Driver Manager version 0.0.9 loaded
[9.782848] cx88/0: cx2388x v4l2 driver version 0.0.9 loaded
[9.794205] input: HDA Digital PCBeep as
/devices/pci:00/:00:1b.0/input/input5
[9.879194] cx88[0]: subsystem: 0070:6906, board: Hauppauge
WinTV-HVR4000(Lite) DVB-S/S2 [card=69,autodetected], frontend(s): 1
[9.914871] input: HDA Intel Line as
/devices/pci:00/:00:1b.0/sound/card0/input6
[9.932037] cx88[0]: TV tuner type -1, Radio tuner type -1
[9.953646] input: HDA Intel Front Mic as
/devices/pci:00/:00:1b.0/sound/card0/input7
[9.981718] input: HDA Intel Rear Mic as
/devices/pci:00/:00:1b.0/sound/card0/input8
[9.996493] input: HDA Intel Line Out CLFE as
/devices/pci:00/:00:1b.0/sound/card0/input9
[ 10.003354] input: HDA Intel Line Out Surround as
/devices/pci:00/:00:1b.0/sound/card0/input10
[ 10.007987] input: HDA Intel Line Out Front as
/devices/pci:00/:00:1b.0/sound/card0/input11
[ 10.450310] tveeprom 9-0050: Hauppauge model 69100, rev B4C3, serial#
7900937
[ 10.453751] tveeprom 9-0050: MAC address is 00:0d:fe:78:8f:09
[ 10.457134] tveeprom 9-0050: tuner model is Conexant CX24118A (idx 123,
type 4)
[ 10.460547] tveeprom 9-0050: TV standards ATSC/DVB Digital (eeprom 0x80)
[ 10.463936] tveeprom 9-0050: audio processor is None (idx 0)
[ 10.467320] tveeprom 9-0050: decoder processor is CX880 (idx 20)
[ 10.470648] tveeprom 9-0050: has no radio, has IR receiver, has no IR
transmitter
[ 10.474038] cx88[0]: hauppauge eeprom: model=69100
[ 10.508060] Registered IR keymap rc-hauppauge
[ 10.518107] input: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0/input12
[ 10.526485] rc0: cx88 IR (Hauppauge WinTV-HVR400 as
/devices/pci:00/:00:1e.0/:05:05.2/rc/rc0
[ 10.530869] cx88[0]/2: cx2388x 8802 Driver Manager
[ 10.534533] cx88[0]/2: found at :05:05.2, rev: 5, irq: 17, latency:
32, mmio: 0xd200
[ 10.541221] cx88[0]/0: found at :05:05.0, rev: 5, irq: 17, latency:
32, mmio: 0xd000
[ 10.545197] IR RC5(x) protocol handler initialized
[ 10.557935]
[ 10.560012] =
[ 10.560012] [ INFO: possible recursive locking detected ]
[ 10.560012] 3.8.0-rc7-main #20 Not tainted
[ 10.560012] -
[ 10.560012] modprobe/469 is trying to acquire lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85604f6]
find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012]
[ 10.560012] but task is already holding lock:
[ 10.560012] (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] other info that might help us debug this:
[ 10.560012] Possible unsafe locking scenario:
[ 10.560012]
[ 10.560012]CPU0
[ 10.560012]
[ 10.560012] lock(hdl-lock);
[ 10.560012] lock(hdl-lock);
[ 10.560012]
[ 10.560012] *** DEADLOCK ***
[ 10.560012]
[ 10.560012] May be due to missing lock nesting notation
[ 10.560012]
[ 10.560012] 3 locks held by modprobe/469:
[ 10.560012] #0: (__lockdep_no_validate__){..}, at: [c03cbcfc]
__driver_attach+0x31/0x6b
[ 10.560012] #1: (__lockdep_no_validate__){..}, at: [c03cbd08]
__driver_attach+0x3d/0x6b
[ 10.560012] #2: (hdl-lock){+.+...}, at: [f85622d3]
v4l2_ctrl_add_handler+0x35/0x91 [videodev]
[ 10.560012]
[ 10.560012] stack backtrace:
[ 10.560012] Pid: 469, comm: modprobe Not tainted 3.8.0-rc7-main #20
[ 10.560012] Call Trace:
[ 10.560012] [c01272cb] ? console_unlock+0x34b/0x374
[ 10.560012] [c015b25a] __lock_acquire+0x1314/0x138a
[ 10.560012] [c015bc94] ? mark_held_locks+0xa1/0xc8
[ 10.560012] [f85604f6] ? find_ref_lock+0x1f/0x39 [videodev]
[ 10.560012] [c015b703] lock_acquire+0xaf/0xcd
[ 10.560012] [f85604f6] ?
