Got this lockdep warning straightaway during boot:
[ 7.435890] ============================================= [ 7.435891] [ INFO: possible recursive locking detected ] [ 7.435893] 3.8.0-next-20130204+pcipatch-xeon+lockdep #20130204+pcipatch Not tainted [ 7.435893] --------------------------------------------- [ 7.435895] modprobe/255 is trying to acquire lock: [ 7.435942] (&dmac->lock){+.+...}, at: [<ffffffffa01767c3>] evo_wait+0x43/0xf0 [nouveau] [ 7.435942] [ 7.435942] but task is already holding lock: [ 7.435964] (&dmac->lock){+.+...}, at: [<ffffffffa01767c3>] evo_wait+0x43/0xf0 [nouveau] [ 7.435964] [ 7.435964] other info that might help us debug this: [ 7.435965] Possible unsafe locking scenario: [ 7.435965] [ 7.435966] CPU0 [ 7.435967] ---- [ 7.435968] lock(&dmac->lock); [ 7.435970] lock(&dmac->lock); [ 7.435970] [ 7.435970] *** DEADLOCK *** [ 7.435970] [ 7.435971] May be due to missing lock nesting notation [ 7.435971] [ 7.435973] 9 locks held by modprobe/255: [ 7.435979] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff814ce26b>] __driver_attach+0x5b/0xb0 [ 7.435982] #1: (&__lockdep_no_validate__){......}, at: [<ffffffff814ce279>] __driver_attach+0x69/0xb0 [ 7.436001] #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa0065e6d>] drm_get_pci_dev+0xbd/0x2a0 [drm] [ 7.436012] #3: (registration_lock){+.+.+.}, at: [<ffffffff81402855>] register_framebuffer+0x25/0x2f0 [ 7.436016] #4: (&fb_info->lock){+.+.+.}, at: [<ffffffff81401736>] lock_fb_info+0x26/0x60 [ 7.436023] #5: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff81096466>] __blocking_notifier_call_chain+0x56/0xc0 [ 7.436035] #6: (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffffa0069d6a>] drm_modeset_lock_all+0x2a/0x70 [drm] [ 7.436046] #7: (&crtc->mutex){+.+.+.}, at: [<ffffffffa0069d94>] drm_modeset_lock_all+0x54/0x70 [drm] [ 7.436068] #8: (&dmac->lock){+.+...}, at: [<ffffffffa01767c3>] evo_wait+0x43/0xf0 [nouveau] [ 7.436068] [ 7.436068] stack backtrace: [ 7.436070] Pid: 255, comm: modprobe Not tainted 3.8.0-next-20130204+pcipatch-xeon+lockdep #20130204+pcipatch [ 7.436072] Call Trace: [ 7.436077] [<ffffffff810d0e87>] __lock_acquire+0x697/0x1a80 [ 7.436080] [<ffffffff810d28f1>] lock_acquire+0xa1/0x200 [ 7.436100] [<ffffffffa01767c3>] ? evo_wait+0x43/0xf0 [nouveau] [ 7.436121] [<ffffffffa01767c3>] ? evo_wait+0x43/0xf0 [nouveau] [ 7.436125] [<ffffffff817946d3>] mutex_lock_nested+0x63/0x3a0 [ 7.436145] [<ffffffffa01767c3>] ? evo_wait+0x43/0xf0 [nouveau] [ 7.436148] [<ffffffff8179490e>] ? mutex_lock_nested+0x29e/0x3a0 [ 7.436168] [<ffffffffa01767c3>] ? evo_wait+0x43/0xf0 [nouveau] [ 7.436170] [<ffffffff810d32ef>] ? mark_held_locks+0xaf/0x110 [ 7.436190] [<ffffffffa01767c3>] evo_wait+0x43/0xf0 [nouveau] [ 7.436212] [<ffffffffa0176d3c>] evo_sync+0x5c/0xf0 [nouveau] [ 7.436233] [<ffffffffa0178e7d>] nv50_display_flip_next+0x5ad/0x5c0 [nouveau]
Regards, Peter Hurley