From recent additional locking in nouveau, it looks like we see
recursive lock acquisition in 3.8-rc6:
nouveau [ DEVICE][0000:01:00.0] BOOT0 : 0x0e7150a2 nouveau [ DEVICE][0000:01:00.0] Chipset: GK107 (NVE7) nouveau [ DEVICE][0000:01:00.0] Family : NVE0 nouveau [ VBIOS][0000:01:00.0] checking PRAMIN for image... nouveau [ VBIOS][0000:01:00.0] ... appears to be valid nouveau [ VBIOS][0000:01:00.0] using image from PRAMIN nouveau [ VBIOS][0000:01:00.0] BIT signature found nouveau [ VBIOS][0000:01:00.0] version 80.07.26.04.01 nouveau [ PFB][0000:01:00.0] RAM type: GDDR5 nouveau [ PFB][0000:01:00.0] RAM size: 1024 MiB nouveau [ PFB][0000:01:00.0] ZCOMP: 0 tags init: gdm main process (960) killed by TERM signal vga_switcheroo: enabled [TTM] Zone kernel: Available graphics memory: 4038258 kiB [TTM] Zone dma32: Available graphics memory: 2097152 kiB [TTM] Initializing pool allocator [TTM] Initializing DMA pool allocator nouveau [ DRM] VRAM: 1024 MiB nouveau [ DRM] GART: 512 MiB nouveau [ DRM] BIT BIOS found nouveau [ DRM] Bios version 80.07.26.04 nouveau [ DRM] TMDS table version 2.0 nouveau [ DRM] DCB version 4.0 nouveau [ DRM] DCB outp 00: 048101b6 0f230010 nouveau [ DRM] DCB outp 01: 018212d6 0f220020 nouveau [ DRM] DCB outp 02: 01021212 00020020 nouveau [ DRM] DCB outp 03: 088324c6 0f220010 nouveau [ DRM] DCB outp 04: 08032402 00020010 nouveau [ DRM] DCB outp 05: 02843862 00020010 nouveau [ DRM] DCB conn 00: 00020047 nouveau [ DRM] DCB conn 01: 02208146 nouveau [ DRM] DCB conn 02: 01104246 nouveau [ DRM] DCB conn 03: 00410361
============================================= [ INFO: possible recursive locking detected ] 3.8.0-rc6-ninja+ #1 Not tainted --------------------------------------------- modprobe/585 is trying to acquire lock: (&subdev->mutex){+.+.+.}, at: [<ffffffffa016c323>] nouveau_instobj_create_+0x43/0x90 [nouveau]
but task is already holding lock: (&subdev->mutex){+.+.+.}, at: [<ffffffffa017672d>] nv50_disp_data_ctor+0x5d/0xd0 [nouveau]
other info that might help us debug this: Possible unsafe locking scenario:
CPU0 ---- lock(&subdev->mutex); lock(&subdev->mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by modprobe/585: #0: (&__lockdep_no_validate__){......}, at: [<ffffffff813075f3>] __driver_attach+0x53/0xb0 #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81307601>] __driver_attach+0x61/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [<ffffffff812ee59c>] drm_get_pci_dev+0xbc/0x2b0 #3: (&subdev->mutex){+.+.+.}, at: [<ffffffffa017672d>] nv50_disp_data_ctor+0x5d/0xd0 [nouveau]
stack backtrace: Pid: 585, comm: modprobe Not tainted 3.8.0-rc6-expert+ #1 Call Trace: [<ffffffff8108fde2>] validate_chain.isra.33+0xd72/0x10d0 [<ffffffff8105fa08>] ? __kernel_text_address+0x58/0x80 [<ffffffff8100575d>] ? print_context_stack+0x5d/0xd0 [<ffffffff81090bc1>] __lock_acquire+0x3a1/0xb60 [<ffffffff8108d504>] ? __lock_is_held+0x54/0x80 [<ffffffff8109184a>] lock_acquire+0x5a/0x70 [<ffffffffa016c323>] ? nouveau_instobj_create_+0x43/0x90 [nouveau] [<ffffffff81558739>] mutex_lock_nested+0x69/0x340 [<ffffffffa016c323>] ? nouveau_instobj_create_+0x43/0x90 [nouveau] [<ffffffffa0152370>] ? nouveau_object_create_+0x60/0xa0 [nouveau] [<ffffffffa016c323>] nouveau_instobj_create_+0x43/0x90 [nouveau] [<ffffffffa016cf8c>] nv50_instobj_ctor+0x4c/0xf0 [nouveau] [<ffffffffa0152163>] nouveau_object_ctor+0x33/0xc0 [nouveau] [<ffffffffa016cd51>] nv50_instmem_alloc+0x21/0x30 [nouveau] [<ffffffffa0150917>] nouveau_gpuobj_create_+0x247/0x2f0 [nouveau] [<ffffffff8155b35a>] ? _raw_spin_unlock_irqrestore+0x3a/0x70 [<ffffffff810921fd>] ? trace_hardirqs_on_caller+0x10d/0x1a0 [<ffffffffa014f4bc>] nouveau_engctx_create_+0x25c/0x2a0 [nouveau] [<ffffffffa0176791>] nv50_disp_data_ctor+0xc1/0xd0 [nouveau] [<ffffffffa0153722>] ? nouveau_subdev_reset+0x52/0x60 [nouveau] [<ffffffffa0152163>] nouveau_object_ctor+0x33/0xc0 [nouveau] [<ffffffffa0152a42>] nouveau_object_new+0x112/0x240 [nouveau] [<ffffffffa01f4b1d>] nv50_display_create+0x18d/0x860 [nouveau] [<ffffffff8105cb5d>] ? __cancel_work_timer+0x6d/0xc0 [<ffffffffa01db8eb>] nouveau_display_create+0x3cb/0x670 [nouveau] [<ffffffffa01cb1bf>] nouveau_drm_load+0x26f/0x590 [nouveau] [<ffffffff81304c99>] ? device_register+0x19/0x20 [<ffffffff812efe91>] ? drm_sysfs_device_add+0x81/0xb0 [<ffffffff812ee65e>] drm_get_pci_dev+0x17e/0x2b0 [<ffffffff81245e56>] ? __pci_set_master+0x26/0x80 [<ffffffffa01cab2a>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff8124a386>] local_pci_probe+0x46/0x80 [<ffffffff8124ac11>] pci_device_probe+0x101/0x110 [<ffffffff813073d6>] driver_probe_device+0x76/0x240 [<ffffffff81307643>] __driver_attach+0xa3/0xb0 [<ffffffff813075a0>] ? driver_probe_device+0x240/0x240 [<ffffffff8130564d>] bus_for_each_dev+0x4d/0x90 [<ffffffff81306f39>] driver_attach+0x19/0x20 [<ffffffff81306af0>] bus_add_driver+0x1a0/0x270 [<ffffffffa023d000>] ? 0xffffffffa023cfff [<ffffffff81307cd2>] driver_register+0x72/0x170 [<ffffffffa023d000>] ? 0xffffffffa023cfff [<ffffffff8124ad0f>] __pci_register_driver+0x5f/0x70 [<ffffffff812ee8a5>] drm_pci_init+0x115/0x130 [<ffffffffa023d000>] ? 0xffffffffa023cfff [<ffffffffa023d000>] ? 0xffffffffa023cfff [<ffffffffa023d04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002da>] do_one_initcall+0x11a/0x170 [<ffffffff8109d044>] load_module+0xe84/0x1470 [<ffffffff81098c30>] ? in_lock_functions+0x20/0x20 [<ffffffff8122c22e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8109d6e7>] sys_init_module+0xb7/0xe0 [<ffffffff8155c156>] system_call_fastpath+0x1a/0x1f [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [drm] No driver support for vblank timestamp query. nouveau W[ DRM] voltage table 0x50 unknown nouveau [ DRM] 4 available performance level(s) nouveau [ DRM] 1: core 209MHz shader 419MHz memory 405MHz voltage 520mV nouveau [ DRM] 2: core 390MHz shader 780MHz memory 1080MHz voltage 610mV nouveau [ DRM] 3: core 1000MHz shader 2000MHz memory 1080MHz voltage 630mV nouveau [ DRM] 4: core 1254MHz shader 2508MHz memory 1080MHz voltage 630mV nouveau [ DRM] c: nouveau [ DRM] MM: using COPY for buffer copies nouveau 0000:01:00.0: No connectors reported connected with modes [drm] Cannot find any crtc or sizes - going 1024x768 nouveau [ DRM] allocated 1024x768 fb: 0x80000, bo ffff88025b966800 nouveau 0000:01:00.0: fb1: nouveaufb frame buffer device [drm] Initialized nouveau 1.1.0 20120801 for 0000:01:00.0 on minor 1 snd_hda_intel 0000:01:00.1: enabling device (0000 -> 0002) hda-intel 0000:01:00.1: Handle VGA-switcheroo audio client snd_hda_intel 0000:01:00.1: irq 49 for MSI/MSI-X input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input11 input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input12 input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input13 hda-intel 0000:01:00.1: Disabling via VGA-switcheroo VGA switcheroo: switched nouveau off nouveau [ DRM] suspending fbcon... nouveau [ DRM] suspending display... nouveau [ DRM] unpinning framebuffer(s)... nouveau [ DRM] evicting buffers... nouveau [ DRM] suspending client object trees... nouveau E[ I2C][0000:01:00.0] AUXCH(3): begin idle timeout 0xffffffff nouveau E[ I2C][0000:01:00.0] AUXCH(2): begin idle timeout 0xffffffff nouveau E[ I2C][0000:01:00.0] AUXCH(1): begin idle timeout 0xffffffff applesmc: light sensor data length set to 10 nouveau E[ I2C][0000:01:00.0] AUXCH(1): begin idle timeout 0xffffffff nouveau E[ I2C][0000:01:00.0] AUXCH(3): begin idle timeout 0xffffffff nouveau E[ I2C][0000:01:00.0] AUXCH(2): begin idle timeout 0xffffffff