[Bugme-new] [Bug 9037] New: ivtv: possible circular locking dependency detected

[bugme-daemon at bugzilla.kernel.org]

http://bugzilla.kernel.org/show_bug.cgi?id=9037

           Summary: ivtv: possible circular locking dependency detected
           Product: Alternate Trees
           Version: 2.5
     KernelVersion: 2.6.23-rc6.mm1.fc8
          Platform: All
        OS/Version: Linux
              Tree: -mm
            Status: NEW
          Severity: normal
          Priority: P1
         Component: mm
        AssignedTo: akpm at osdl.org
        ReportedBy: Nicolas.Mailhot at LaPoste.net
                CC: hverkuil at xs4all.nl


Distribution: Fedora Devel
Hardware Environment: PVR 150

Problem Description:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.23-0.186.rc6.mm1.fc8 #1
-------------------------------------------------------
totem/3254 is trying to acquire lock:
 (&itv->serialize_lock){--..}, at: [<ffffffff88220cd0>]
ivtv_v4l2_open+0x93/0x2b3 [ivtv]

but task is already holding lock:
 (videodev_lock){--..}, at: [<ffffffff8819f087>] video_open+0x38/0x157
[videodev]

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (videodev_lock){--..}:
       [<ffffffff81057529>] __lock_acquire+0xa79/0xc72
       [<ffffffff81057b0f>] lock_acquire+0x5a/0x73
       [<ffffffff81264abd>] __mutex_lock_slowpath+0xe6/0x286
       [<ffffffff8819c1da>] video_register_device+0x9c/0x232 [videodev]
       [<ffffffff88229f1e>] ivtv_streams_setup+0x25b/0x3e8 [ivtv]
       [<ffffffff882200a2>] ivtv_probe+0x10e7/0x12db [ivtv]
       [<ffffffff81132902>] pci_device_probe+0xd1/0x138
       [<ffffffff8119cee3>] driver_probe_device+0xf7/0x174
       [<ffffffff8119d0a8>] __driver_attach+0x90/0xcc
       [<ffffffff8119c25c>] bus_for_each_dev+0x43/0x6e
       [<ffffffff8119c5e2>] bus_add_driver+0x7a/0x1c4
       [<ffffffff81132ae4>] __pci_register_driver+0x68/0x9a
       [<ffffffff8821ef42>] module_start+0x8b/0xb7 [ivtv]
       [<ffffffff8105f900>] sys_init_module+0x1601/0x17a6
       [<ffffffff8100bf4e>] system_call+0x7e/0x83
       [<000000316e2d200a>] 0x316e2d200a
       [<ffffffffffffffff>] 0xffffffffffffffff

-> #0 (&itv->serialize_lock){--..}:
       [<ffffffff8105742a>] __lock_acquire+0x97a/0xc72
       [<ffffffff81057b0f>] lock_acquire+0x5a/0x73
       [<ffffffff81264abd>] __mutex_lock_slowpath+0xe6/0x286
       [<ffffffff88220cd0>] ivtv_v4l2_open+0x93/0x2b3 [ivtv]
       [<ffffffff8819f136>] video_open+0xe7/0x157 [videodev]
       [<ffffffff810a4282>] chrdev_open+0x149/0x198
       [<ffffffff810a03b8>] __dentry_open+0xd9/0x1b0
       [<ffffffff810a0543>] do_filp_open+0x2a/0x38
       [<ffffffff810a0597>] do_sys_open+0x46/0xc3
       [<ffffffff8100c0e5>] tracesys+0xdc/0xe1
       [<000000316ee0dd9f>] 0x316ee0dd9f
       [<ffffffffffffffff>] 0xffffffffffffffff

other info that might help us debug this:

1 lock held by totem/3254:
 #0:  (videodev_lock){--..}, at: [<ffffffff8819f087>] video_open+0x38/0x157
[videodev]

stack backtrace:

Call Trace:
 [<ffffffff8100d69e>] show_trace+0x34/0x4f
 [<ffffffff8100d6cb>] dump_stack+0x12/0x17
 [<ffffffff8105597c>] print_circular_bug_tail+0x69/0x72
 [<ffffffff8105742a>] __lock_acquire+0x97a/0xc72
 [<ffffffff81057b0f>] lock_acquire+0x5a/0x73
 [<ffffffff81264abd>] __mutex_lock_slowpath+0xe6/0x286
 [<ffffffff88220cd0>] :ivtv:ivtv_v4l2_open+0x93/0x2b3
 [<ffffffff8819f136>] :videodev:video_open+0xe7/0x157
 [<ffffffff810a4282>] chrdev_open+0x149/0x198
 [<ffffffff810a03b8>] __dentry_open+0xd9/0x1b0
 [<ffffffff810a0543>] do_filp_open+0x2a/0x38
 [<ffffffff810a0597>] do_sys_open+0x46/0xc3
 [<ffffffff8100c0e5>] tracesys+0xdc/0xe1
 [<000000316ee0dd9f>]

INFO: lockdep is turned off.
ivtv0: Loaded v4l-cx2341x-enc.fw firmware (376836 bytes)
ivtv0: Encoder revision: 0x02060039
cx25840 2-0044: loaded v4l-cx25840.fw firmware (16382 bytes)


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