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* Re: Slow path and cpu lock warnings - MC Next Gen
       [not found] ` <5640C1DA.7040100@osg.samsung.com>
@ 2015-11-11 12:30   ` Mauro Carvalho Chehab
  2015-11-11 14:22     ` Shuah Khan
  0 siblings, 1 reply; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-11-11 12:30 UTC (permalink / raw)
  To: Shuah Khan; +Cc: Javier Martinez Canillas, Linux Media Mailing List

Em Mon, 09 Nov 2015 08:55:06 -0700
Shuah Khan <shuahkh@osg.samsung.com> escreveu:

> On 11/09/2015 08:51 AM, Shuah Khan wrote:
> > As I mentioned on the IRC, here is the log for the problems I am seeing.
> > I have to do eject HVR 950Q TV stick to see the problem.
> > 
> > mc_next_gen.v8.4 branch with no changes.
> > 
> > I can test and debug this week.
> > 
> > thanks,
> > -- Shuah
> >   
> 
> Forgot to cc linux-media, just in case others are interested
> and have ideas on debugging.
> 
> thanks,
> -- Shuah

> [    8.558049] ======================================================
> [    8.558056] [ INFO: possible circular locking dependency detected ]
> [    8.558063] 4.2.0-rc2+ #21 Not tainted
> [    8.558070] -------------------------------------------------------
> [    8.558077] systemd-udevd/143 is trying to acquire lock:
> [    8.558084]  (init_mutex){+.+.+.}, at: [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> [    8.558104] 
>                but task is already holding lock:
> [    8.558114]  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
> [    8.558133] 
>                which lock already depends on the new lock.
> 
> [    8.558147] 
>                the existing dependency chain (in reverse order) is:
> [    8.558158] 
>                -> #1 (&(&backlight_notifier)->rwsem){++++..}:  
> [    8.558170]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> [    8.558180]        [<ffffffff817fb006>] down_write+0x36/0x70
> [    8.558189]        [<ffffffff8107fdc1>] blocking_notifier_chain_register+0x21/0xb0
> [    8.558202]        [<ffffffff81424c98>] backlight_register_notifier+0x18/0x20
> [    8.558212]        [<ffffffffa0002019>] acpi_video_get_backlight_type+0xfa/0x163 [video]
> [    8.558225]        [<ffffffffa000167e>] acpi_video_bus_add+0x686/0xdfa [video]
> [    8.558237]        [<ffffffff814371b0>] acpi_device_probe+0x50/0xf7
> [    8.558247]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> [    8.558257]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> [    8.558266]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> [    8.558275]        [<ffffffff814daece>] driver_attach+0x1e/0x20
> [    8.558287]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> [    8.558296]        [<ffffffff814dc280>] driver_register+0x60/0xe0
> [    8.558304]        [<ffffffff81437936>] acpi_bus_register_driver+0x3b/0x43
> [    8.558313]        [<ffffffffa0000328>] acpi_video_register+0x6e/0x90 [video]
> [    8.558322]        [<ffffffffa000b087>] hid_generic_exit+0x87/0x1000 [hid_generic]
> [    8.558334]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> [    8.558344]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> [    8.558353]        [<ffffffff810f1900>] load_module+0x2170/0x2780
> [    8.558363]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> [    8.558372]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> [    8.558381] 
>                -> #0 (init_mutex){+.+.+.}:  
> [    8.558392]        [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
> [    8.558401]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> [    8.558409]        [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
> [    8.558417]        [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> [    8.558430]        [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
> [    8.558442]        [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
> [    8.558451]        [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
> [    8.558462]        [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
> [    8.558474]        [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
> [    8.558483]        [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
> [    8.558543]        [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
> [    8.558585]        [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
> [    8.558625]        [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
> [    8.558667]        [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
> [    8.558706]        [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
> [    8.558728]        [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
> [    8.558747]        [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
> [    8.558783]        [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
> [    8.558792]        [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
> [    8.558800]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> [    8.558809]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> [    8.558818]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> [    8.558827]        [<ffffffff814daece>] driver_attach+0x1e/0x20
> [    8.558835]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> [    8.558844]        [<ffffffff814dc280>] driver_register+0x60/0xe0
> [    8.558852]        [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
> [    8.558860]        [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
> [    8.558879]        [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
> [    8.558911]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> [    8.558920]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> [    8.558928]        [<ffffffff810f1900>] load_module+0x2170/0x2780
> [    8.558937]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> [    8.558945]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> [    8.558954] 
>                other info that might help us debug this:
> 
> [    8.558968]  Possible unsafe locking scenario:
> 
> [    8.558978]        CPU0                    CPU1
> [    8.558984]        ----                    ----
> [    8.558989]   lock(&(&backlight_notifier)->rwsem);
> [    8.558997]                                lock(init_mutex);
> [    8.559004]                                lock(&(&backlight_notifier)->rwsem);
> [    8.559015]   lock(init_mutex);
> [    8.559021] 
>                 *** DEADLOCK ***
> 
> [    8.559035] 4 locks held by systemd-udevd/143:
> [    8.559041]  #0:  (&dev->mutex){......}, at: [<ffffffff814db99b>] __driver_attach+0x4b/0xa0
> [    8.559056]  #1:  (&dev->mutex){......}, at: [<ffffffff814db9a9>] __driver_attach+0x59/0xa0
> [    8.559072]  #2:  (drm_global_mutex){+.+.+.}, at: [<ffffffffa00331f6>] drm_dev_register+0x26/0x100 [drm]
> [    8.559097]  #3:  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
> [    8.559113] 
>                stack backtrace:
> [    8.559124] CPU: 2 PID: 143 Comm: systemd-udevd Not tainted 4.2.0-rc2+ #21
> [    8.559132] Hardware name: Hewlett-Packard HP ProBook 6475b/180F, BIOS 68TTU Ver. F.04 08/03/2012
> [    8.559143]  ffffffff8285ace0 ffff88002b09f378 ffffffff817f4254 ffffffff810c155a
> [    8.559156]  ffffffff8285ace0 ffff88002b09f3c8 ffffffff810ac6a3 0000000000000003
> [    8.559169]  ffff88002b09f438 ffff88002b09f3c8 ffff88002b06b398 ffff88002b06a600
> [    8.559181] Call Trace:
> [    8.559190]  [<ffffffff817f4254>] dump_stack+0x45/0x57
> [    8.559208]  [<ffffffff810c155a>] ? console_unlock+0x1da/0x580
> [    8.559216]  [<ffffffff810ac6a3>] print_circular_bug+0x1e3/0x250
> [    8.559225]  [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
> [    8.559234]  [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> [    8.559243]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
> [    8.559255]  [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
> [    8.559264]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
> [    8.559277]  [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> [    8.559289]  [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
> [    8.559301]  [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
> [    8.559310]  [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
> [    8.559319]  [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
> [    8.559327]  [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
> [    8.559374]  [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
> [    8.559416]  [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
> [    8.559455]  [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
> [    8.559481]  [<ffffffffa0038c1b>] ? drm_mode_crtc_set_gamma_size+0x5b/0x70 [drm]
> [    8.559523]  [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
> [    8.559566]  [<ffffffffa03071d8>] ? radeon_ib_ring_tests+0x58/0xc0 [radeon]
> [    8.559601]  [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
> [    8.559620]  [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
> [    8.559639]  [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
> [    8.559674]  [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
> [    8.559683]  [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
> [    8.559691]  [<ffffffff813f47d0>] ? pci_match_device+0xe0/0x110
> [    8.559699]  [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
> [    8.559708]  [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> [    8.559717]  [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> [    8.559726]  [<ffffffff814db950>] ? driver_probe_device+0x470/0x470
> [    8.559734]  [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> [    8.559743]  [<ffffffff814daece>] driver_attach+0x1e/0x20
> [    8.559752]  [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> [    8.559760]  [<ffffffff814dc280>] driver_register+0x60/0xe0
> [    8.559767]  [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
> [    8.559786]  [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
> [    8.559794]  [<ffffffffa039d000>] ? 0xffffffffa039d000
> [    8.559825]  [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
> [    8.559834]  [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> [    8.559843]  [<ffffffff817f3146>] ? do_init_module+0x28/0x1e9
> [    8.559852]  [<ffffffff811c5c3b>] ? kmem_cache_alloc_trace+0xbb/0x160
> [    8.559862]  [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> [    8.559870]  [<ffffffff810f1900>] load_module+0x2170/0x2780
> [    8.559878]  [<ffffffff810edd30>] ? __symbol_put+0x40/0x40
> [    8.559888]  [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> [    8.559897]  [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f

Sorry, but I fail to see how this is related to the V4L2 subsystem.

At least on my eyes, it seems that the bug is somewhere at the Radeon
driver.

Regards,
Mauro

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Slow path and cpu lock warnings - MC Next Gen
  2015-11-11 12:30   ` Slow path and cpu lock warnings - MC Next Gen Mauro Carvalho Chehab
@ 2015-11-11 14:22     ` Shuah Khan
  2015-11-11 15:36       ` Mauro Carvalho Chehab
  0 siblings, 1 reply; 6+ messages in thread
From: Shuah Khan @ 2015-11-11 14:22 UTC (permalink / raw)
  To: Mauro Carvalho Chehab
  Cc: Javier Martinez Canillas, Linux Media Mailing List, Shuah Khan

On 11/11/2015 05:30 AM, Mauro Carvalho Chehab wrote:
> Em Mon, 09 Nov 2015 08:55:06 -0700
> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
> 
>> On 11/09/2015 08:51 AM, Shuah Khan wrote:
>>> As I mentioned on the IRC, here is the log for the problems I am seeing.
>>> I have to do eject HVR 950Q TV stick to see the problem.
>>>
>>> mc_next_gen.v8.4 branch with no changes.
>>>
>>> I can test and debug this week.
>>>
>>> thanks,
>>> -- Shuah
>>>   
>>
>> Forgot to cc linux-media, just in case others are interested
>> and have ideas on debugging.
>>
>> thanks,
>> -- Shuah
> 
>> [    8.558049] ======================================================
>> [    8.558056] [ INFO: possible circular locking dependency detected ]
>> [    8.558063] 4.2.0-rc2+ #21 Not tainted
>> [    8.558070] -------------------------------------------------------
>> [    8.558077] systemd-udevd/143 is trying to acquire lock:
>> [    8.558084]  (init_mutex){+.+.+.}, at: [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>> [    8.558104] 
>>                but task is already holding lock:
>> [    8.558114]  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
>> [    8.558133] 
>>                which lock already depends on the new lock.
>>
>> [    8.558147] 
>>                the existing dependency chain (in reverse order) is:
>> [    8.558158] 
>>                -> #1 (&(&backlight_notifier)->rwsem){++++..}:  
>> [    8.558170]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>> [    8.558180]        [<ffffffff817fb006>] down_write+0x36/0x70
>> [    8.558189]        [<ffffffff8107fdc1>] blocking_notifier_chain_register+0x21/0xb0
>> [    8.558202]        [<ffffffff81424c98>] backlight_register_notifier+0x18/0x20
>> [    8.558212]        [<ffffffffa0002019>] acpi_video_get_backlight_type+0xfa/0x163 [video]
>> [    8.558225]        [<ffffffffa000167e>] acpi_video_bus_add+0x686/0xdfa [video]
>> [    8.558237]        [<ffffffff814371b0>] acpi_device_probe+0x50/0xf7
>> [    8.558247]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>> [    8.558257]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>> [    8.558266]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>> [    8.558275]        [<ffffffff814daece>] driver_attach+0x1e/0x20
>> [    8.558287]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>> [    8.558296]        [<ffffffff814dc280>] driver_register+0x60/0xe0
>> [    8.558304]        [<ffffffff81437936>] acpi_bus_register_driver+0x3b/0x43
>> [    8.558313]        [<ffffffffa0000328>] acpi_video_register+0x6e/0x90 [video]
>> [    8.558322]        [<ffffffffa000b087>] hid_generic_exit+0x87/0x1000 [hid_generic]
>> [    8.558334]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>> [    8.558344]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>> [    8.558353]        [<ffffffff810f1900>] load_module+0x2170/0x2780
>> [    8.558363]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>> [    8.558372]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
>> [    8.558381] 
>>                -> #0 (init_mutex){+.+.+.}:  
>> [    8.558392]        [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
>> [    8.558401]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>> [    8.558409]        [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
>> [    8.558417]        [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>> [    8.558430]        [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
>> [    8.558442]        [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
>> [    8.558451]        [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
>> [    8.558462]        [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
>> [    8.558474]        [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
>> [    8.558483]        [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
>> [    8.558543]        [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
>> [    8.558585]        [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
>> [    8.558625]        [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
>> [    8.558667]        [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
>> [    8.558706]        [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
>> [    8.558728]        [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
>> [    8.558747]        [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
>> [    8.558783]        [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
>> [    8.558792]        [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
>> [    8.558800]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>> [    8.558809]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>> [    8.558818]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>> [    8.558827]        [<ffffffff814daece>] driver_attach+0x1e/0x20
>> [    8.558835]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>> [    8.558844]        [<ffffffff814dc280>] driver_register+0x60/0xe0
>> [    8.558852]        [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
>> [    8.558860]        [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
>> [    8.558879]        [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
>> [    8.558911]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>> [    8.558920]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>> [    8.558928]        [<ffffffff810f1900>] load_module+0x2170/0x2780
>> [    8.558937]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>> [    8.558945]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
>> [    8.558954] 
>>                other info that might help us debug this:
>>
>> [    8.558968]  Possible unsafe locking scenario:
>>
>> [    8.558978]        CPU0                    CPU1
>> [    8.558984]        ----                    ----
>> [    8.558989]   lock(&(&backlight_notifier)->rwsem);
>> [    8.558997]                                lock(init_mutex);
>> [    8.559004]                                lock(&(&backlight_notifier)->rwsem);
>> [    8.559015]   lock(init_mutex);
>> [    8.559021] 
>>                 *** DEADLOCK ***
>>
>> [    8.559035] 4 locks held by systemd-udevd/143:
>> [    8.559041]  #0:  (&dev->mutex){......}, at: [<ffffffff814db99b>] __driver_attach+0x4b/0xa0
>> [    8.559056]  #1:  (&dev->mutex){......}, at: [<ffffffff814db9a9>] __driver_attach+0x59/0xa0
>> [    8.559072]  #2:  (drm_global_mutex){+.+.+.}, at: [<ffffffffa00331f6>] drm_dev_register+0x26/0x100 [drm]
>> [    8.559097]  #3:  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
>> [    8.559113] 
>>                stack backtrace:
>> [    8.559124] CPU: 2 PID: 143 Comm: systemd-udevd Not tainted 4.2.0-rc2+ #21
>> [    8.559132] Hardware name: Hewlett-Packard HP ProBook 6475b/180F, BIOS 68TTU Ver. F.04 08/03/2012
>> [    8.559143]  ffffffff8285ace0 ffff88002b09f378 ffffffff817f4254 ffffffff810c155a
>> [    8.559156]  ffffffff8285ace0 ffff88002b09f3c8 ffffffff810ac6a3 0000000000000003
>> [    8.559169]  ffff88002b09f438 ffff88002b09f3c8 ffff88002b06b398 ffff88002b06a600
>> [    8.559181] Call Trace:
>> [    8.559190]  [<ffffffff817f4254>] dump_stack+0x45/0x57
>> [    8.559208]  [<ffffffff810c155a>] ? console_unlock+0x1da/0x580
>> [    8.559216]  [<ffffffff810ac6a3>] print_circular_bug+0x1e3/0x250
>> [    8.559225]  [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
>> [    8.559234]  [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>> [    8.559243]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
>> [    8.559255]  [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
>> [    8.559264]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
>> [    8.559277]  [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>> [    8.559289]  [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
>> [    8.559301]  [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
>> [    8.559310]  [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
>> [    8.559319]  [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
>> [    8.559327]  [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
>> [    8.559374]  [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
>> [    8.559416]  [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
>> [    8.559455]  [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
>> [    8.559481]  [<ffffffffa0038c1b>] ? drm_mode_crtc_set_gamma_size+0x5b/0x70 [drm]
>> [    8.559523]  [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
>> [    8.559566]  [<ffffffffa03071d8>] ? radeon_ib_ring_tests+0x58/0xc0 [radeon]
>> [    8.559601]  [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
>> [    8.559620]  [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
>> [    8.559639]  [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
>> [    8.559674]  [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
>> [    8.559683]  [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
>> [    8.559691]  [<ffffffff813f47d0>] ? pci_match_device+0xe0/0x110
>> [    8.559699]  [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
>> [    8.559708]  [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>> [    8.559717]  [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>> [    8.559726]  [<ffffffff814db950>] ? driver_probe_device+0x470/0x470
>> [    8.559734]  [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>> [    8.559743]  [<ffffffff814daece>] driver_attach+0x1e/0x20
>> [    8.559752]  [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>> [    8.559760]  [<ffffffff814dc280>] driver_register+0x60/0xe0
>> [    8.559767]  [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
>> [    8.559786]  [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
>> [    8.559794]  [<ffffffffa039d000>] ? 0xffffffffa039d000
>> [    8.559825]  [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
>> [    8.559834]  [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>> [    8.559843]  [<ffffffff817f3146>] ? do_init_module+0x28/0x1e9
>> [    8.559852]  [<ffffffff811c5c3b>] ? kmem_cache_alloc_trace+0xbb/0x160
>> [    8.559862]  [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>> [    8.559870]  [<ffffffff810f1900>] load_module+0x2170/0x2780
>> [    8.559878]  [<ffffffff810edd30>] ? __symbol_put+0x40/0x40
>> [    8.559888]  [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>> [    8.559897]  [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> 
> Sorry, but I fail to see how this is related to the V4L2 subsystem.
> 
> At least on my eyes, it seems that the bug is somewhere at the Radeon
> driver.
> 

Mauro,

I think you didn't look down the dmesg far enough. The following is the
problem I am talking about and you will see media_device_unregister()
on the stack. This occurs as soon as the device is removed.

thanks,
-- Shuah

[  304.245575] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
[kworker/2:1:56]
[  304.245587] Modules linked in: snd_usb_audio snd_usbmidi_lib
snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
snd_hda_codec_generic snd_hda_codec_hdmi
[  304.245661]  snd_hda_intel microcode snd_hda_codec hp_accel
tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
[  304.245709] irq event stamp: 1850
[  304.245712] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
_raw_spin_unlock_irq+0x30/0x40
[  304.245722] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
_raw_spin_lock_irq+0x17/0x50
[  304.245727] softirqs last  enabled at (512): [<ffffffff81799f7d>]
addrconf_verify_rtnl+0x23d/0x500
[  304.245735] softirqs last disabled at (506): [<ffffffff81799d63>]
addrconf_verify_rtnl+0x23/0x500
[  304.245744] CPU: 2 PID: 56 Comm: kworker/2:1 Not tainted 4.2.0-rc2+ #21
[  304.245747] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
BIOS 68TTU Ver. F.04 08/03/2012
[  304.245754] Workqueue: usb_hub_wq hub_event
[  304.245758] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
ffff880218dec000
[  304.245761] RIP: 0010:[<ffffffff813bf2ea>]  [<ffffffff813bf2ea>]
delay_tsc+0x1a/0x50
[  304.245769] RSP: 0018:ffff880218def938  EFLAGS: 00000206
[  304.245772] RAX: 000000001d95bc8c RBX: 0000000180100008 RCX:
000000001d95bc8c
[  304.245775] RDX: 00000000000000ad RSI: 0000000000000002 RDI:
0000000000000001
[  304.245777] RBP: ffff880218def938 R08: 0000000000000001 R09:
0000000000000000
[  304.245780] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff817fe161
[  304.245783] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
ffffffff810d021e
[  304.245786] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
knlGS:0000000000000000
[  304.245789] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  304.245792] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
00000000000407e0
[  304.245794] Stack:
[  304.245796]  ffff880218def948 ffffffff813bf20f ffff880218def978
ffffffff810b428c
[  304.245802]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
ffff880231f1fd40
[  304.245807]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
ffffffff8160f844
[  304.245812] Call Trace:
[  304.245819]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  304.245826]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  304.245830]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  304.245837]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  304.245841]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  304.245846]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  304.245851]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  304.245859]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  304.245868]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  304.245874]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  304.245878]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  304.245883]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  304.245888]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  304.245893]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  304.245900]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  304.245904]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  304.245910]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  304.245914]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  304.245919]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  304.245923]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  304.245927]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  304.245931]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  304.245937]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  304.245943]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  304.245947]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  304.245952]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  304.245957]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  304.245961]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  304.245965]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  304.245971]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  304.245975]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  304.245980]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  304.245982] Code: 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00
0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f
ae f0 <0f> 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90
[  332.243453] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
[kworker/2:1:56]
[  332.243464] Modules linked in: snd_usb_audio snd_usbmidi_lib
snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
snd_hda_codec_generic snd_hda_codec_hdmi
[  332.243542]  snd_hda_intel microcode snd_hda_codec hp_accel
tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
[  332.243592] irq event stamp: 1850
[  332.243595] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
_raw_spin_unlock_irq+0x30/0x40
[  332.243605] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
_raw_spin_lock_irq+0x17/0x50
[  332.243612] softirqs last  enabled at (512): [<ffffffff81799f7d>]
addrconf_verify_rtnl+0x23d/0x500
[  332.243619] softirqs last disabled at (506): [<ffffffff81799d63>]
addrconf_verify_rtnl+0x23/0x500
[  332.243628] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
 4.2.0-rc2+ #21
[  332.243632] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
BIOS 68TTU Ver. F.04 08/03/2012
[  332.243638] Workqueue: usb_hub_wq hub_event
[  332.243642] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
ffff880218dec000
[  332.243645] RIP: 0010:[<ffffffff813bf2e5>]  [<ffffffff813bf2e5>]
delay_tsc+0x15/0x50
[  332.243653] RSP: 0018:ffff880218def938  EFLAGS: 00000202
[  332.243656] RAX: 0000000015191edb RBX: 0000000180100008 RCX:
0000000015191d34
[  332.243659] RDX: 00000000000000bc RSI: 0000000000000002 RDI:
0000000000000001
[  332.243662] RBP: ffff880218def938 R08: 0000000000000001 R09:
0000000000000000
[  332.243665] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff817fe161
[  332.243667] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
ffffffff810d021e
[  332.243671] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
knlGS:0000000000000000
[  332.243674] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  332.243677] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
00000000000407e0
[  332.243679] Stack:
[  332.243681]  ffff880218def948 ffffffff813bf20f ffff880218def978
ffffffff810b428c
[  332.243687]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
ffff880231f1fd40
[  332.243692]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
ffffffff8160f844
[  332.243697] Call Trace:
[  332.243704]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  332.243711]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  332.243715]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  332.243721]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  332.243726]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  332.243730]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  332.243734]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  332.243743]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  332.243749]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  332.243754]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  332.243758]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  332.243763]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  332.243768]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  332.243773]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  332.243780]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  332.243784]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  332.243790]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  332.243794]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  332.243799]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  332.243804]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  332.243808]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  332.243812]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  332.243817]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  332.243823]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  332.243827]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  332.243832]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  332.243837]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  332.243841]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  332.243846]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  332.243851]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  332.243855]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  332.243860]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  332.243862] Code: ff 15 68 bb ae 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84
00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0
0f 31 <89> c1 0f ae f0 0f 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39
[  344.082652] INFO: rcu_sched self-detected stall on CPU { 2}  (t=16250
jiffies g=16088 c=16087 q=6192)
[  344.082671] Task dump for CPU 2:
[  344.082675] kworker/2:1     R  running task        0    56      2
0x00000008
[  344.082686] Workqueue: usb_hub_wq hub_event
[  344.082689]  0000000000000002 ffff88023ed03d58 ffffffff8108d999
ffffffff8108d8d1
[  344.082695]  0000000000000000 0000000000000002 ffffffff81e4ffc0
ffff88023ed03d78
[  344.082701]  ffffffff8109089b ffff88023ed16840 0000000000000003
ffff88023ed03da8
[  344.082706] Call Trace:
[  344.082709]  <IRQ>  [<ffffffff8108d999>] sched_show_task+0x129/0x230
[  344.082721]  [<ffffffff8108d8d1>] ? sched_show_task+0x61/0x230
[  344.082727]  [<ffffffff8109089b>] dump_cpu_task+0x3b/0x50
[  344.082733]  [<ffffffff810cd58e>] rcu_dump_cpu_stacks+0x8e/0xe0
[  344.082738]  [<ffffffff810d0906>] rcu_check_callbacks+0x486/0x770
[  344.082743]  [<ffffffff810a9580>] ? cpuacct_account_field+0xd0/0x1a0
[  344.082747]  [<ffffffff810a94b5>] ? cpuacct_account_field+0x5/0x1a0
[  344.082753]  [<ffffffff810e6212>] ? tick_sched_timer+0x22/0x80
[  344.082758]  [<ffffffff810e61f0>] ? tick_sched_do_timer+0x30/0x30
[  344.082762]  [<ffffffff810d5c89>] update_process_times+0x39/0x60
[  344.082767]  [<ffffffff810e5b25>] tick_sched_handle.isra.16+0x25/0x60
[  344.082772]  [<ffffffff810e6234>] tick_sched_timer+0x44/0x80
[  344.082776]  [<ffffffff810d653e>] __hrtimer_run_queues+0xce/0x270
[  344.082781]  [<ffffffff810d6ceb>] hrtimer_interrupt+0xab/0x1b0
[  344.082787]  [<ffffffff8103807c>] local_apic_timer_interrupt+0x3c/0x70
[  344.082792]  [<ffffffff81800031>] smp_apic_timer_interrupt+0x41/0x60
[  344.082796]  [<ffffffff817fe40d>] apic_timer_interrupt+0x6d/0x80
[  344.082799]  <EOI>  [<ffffffff813bf2e3>] ? delay_tsc+0x13/0x50
[  344.082808]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  344.082812]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  344.082816]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  344.082821]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  344.082825]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  344.082829]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  344.082833]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  344.082841]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  344.082846]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  344.082851]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  344.082854]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  344.082860]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  344.082865]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  344.082869]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  344.082875]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  344.082880]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  344.082885]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  344.082889]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  344.082894]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  344.082898]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  344.082902]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  344.082906]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  344.082911]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  344.082917]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  344.082921]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  344.082926]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  344.082931]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  344.082935]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  344.082939]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  344.082944]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  344.082949]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  344.082953]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  368.241164] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
[kworker/2:1:56]
[  368.241173] Modules linked in: snd_usb_audio snd_usbmidi_lib
snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
snd_hda_codec_generic snd_hda_codec_hdmi
[  368.241251]  snd_hda_intel microcode snd_hda_codec hp_accel
tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
[  368.241300] irq event stamp: 1850
[  368.241303] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
_raw_spin_unlock_irq+0x30/0x40
[  368.241313] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
_raw_spin_lock_irq+0x17/0x50
[  368.241318] softirqs last  enabled at (512): [<ffffffff81799f7d>]
addrconf_verify_rtnl+0x23d/0x500
[  368.241326] softirqs last disabled at (506): [<ffffffff81799d63>]
addrconf_verify_rtnl+0x23/0x500
[  368.241335] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
 4.2.0-rc2+ #21
[  368.241339] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
BIOS 68TTU Ver. F.04 08/03/2012
[  368.241345] Workqueue: usb_hub_wq hub_event
[  368.241349] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
ffff880218dec000
[  368.241352] RIP: 0010:[<ffffffff813bf2ea>]  [<ffffffff813bf2ea>]
delay_tsc+0x1a/0x50
[  368.241359] RSP: 0018:ffff880218def938  EFLAGS: 00000206
[  368.241363] RAX: 000000005363a164 RBX: 0000000180100008 RCX:
000000005363a164
[  368.241365] RDX: 00000000000000cf RSI: 0000000000000002 RDI:
0000000000000001
[  368.241368] RBP: ffff880218def938 R08: 0000000000000001 R09:
0000000000000000
[  368.241370] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff817fe161
[  368.241373] R13: ffffffff810d021e R14: ffff880218def8c8 R15:
0140000000000000
[  368.241377] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
knlGS:0000000000000000
[  368.241379] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  368.241382] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
00000000000407e0
[  368.241384] Stack:
[  368.241387]  ffff880218def948 ffffffff813bf20f ffff880218def978
ffffffff810b428c
[  368.241392]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
ffff880231f1fd40
[  368.241398]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
ffffffff8160f844
[  368.241403] Call Trace:
[  368.241410]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  368.241416]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  368.241421]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  368.241427]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  368.241431]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  368.241436]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  368.241440]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  368.241449]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  368.241454]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  368.241460]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  368.241464]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  368.241469]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  368.241474]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  368.241479]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  368.241486]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  368.241491]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  368.241496]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  368.241501]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  368.241505]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  368.241510]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  368.241514]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  368.241518]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  368.241523]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  368.241529]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  368.241534]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  368.241539]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  368.241544]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  368.241548]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  368.241552]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  368.241558]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  368.241562]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  368.241567]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  368.241569] Code: 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00
0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f
ae f0 <0f> 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90
[  396.239591] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 23s!
[kworker/2:1:56]
[  396.239601] Modules linked in: snd_usb_audio snd_usbmidi_lib
snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
snd_hda_codec_generic snd_hda_codec_hdmi
[  396.239676]  snd_hda_intel microcode snd_hda_codec hp_accel
tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
[  396.239724] irq event stamp: 1850
[  396.239727] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
_raw_spin_unlock_irq+0x30/0x40
[  396.239736] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
_raw_spin_lock_irq+0x17/0x50
[  396.239742] softirqs last  enabled at (512): [<ffffffff81799f7d>]
addrconf_verify_rtnl+0x23d/0x500
[  396.239749] softirqs last disabled at (506): [<ffffffff81799d63>]
addrconf_verify_rtnl+0x23/0x500
[  396.239758] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
 4.2.0-rc2+ #21
[  396.239761] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
BIOS 68TTU Ver. F.04 08/03/2012
[  396.239768] Workqueue: usb_hub_wq hub_event
[  396.239772] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
ffff880218dec000
[  396.239775] RIP: 0010:[<ffffffff813bf2e5>]  [<ffffffff813bf2e5>]
delay_tsc+0x15/0x50
[  396.239782] RSP: 0018:ffff880218def938  EFLAGS: 00000206
[  396.239785] RAX: 000000004afa4fa4 RBX: 0000000180100008 RCX:
000000004afa42a6
[  396.239788] RDX: 00000000000000de RSI: 0000000000000002 RDI:
0000000000000001
[  396.239791] RBP: ffff880218def938 R08: 0000000000000001 R09:
0000000000000000
[  396.239793] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff817fe161
[  396.239796] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
ffffffff810d021e
[  396.239799] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
knlGS:0000000000000000
[  396.239802] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  396.239805] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
00000000000407e0
[  396.239807] Stack:
[  396.239809]  ffff880218def948 ffffffff813bf20f ffff880218def978
ffffffff810b428c
[  396.239815]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
ffff880231f1fd40
[  396.239820]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
ffffffff8160f844
[  396.239825] Call Trace:
[  396.239833]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  396.239839]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  396.239844]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  396.239850]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  396.239855]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  396.239859]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  396.239864]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  396.239872]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  396.239878]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  396.239883]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  396.239887]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  396.239892]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  396.239898]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  396.239902]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  396.239909]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  396.239914]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  396.239919]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  396.239924]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  396.239929]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  396.239933]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  396.239937]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  396.239941]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  396.239946]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  396.239953]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  396.239957]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  396.239962]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  396.239967]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  396.239971]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  396.239976]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  396.239981]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  396.239986]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  396.239990]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  396.239992] Code: ff 15 68 bb ae 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84
00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0
0f 31 <89> c1 0f ae f0 0f 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39
[  424.238131] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 23s!
[kworker/2:1:56]
[  424.238143] Modules linked in: snd_usb_audio snd_usbmidi_lib
snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
snd_hda_codec_generic snd_hda_codec_hdmi
[  424.238218]  snd_hda_intel microcode snd_hda_codec hp_accel
tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
[  424.238267] irq event stamp: 1850
[  424.238270] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
_raw_spin_unlock_irq+0x30/0x40
[  424.238280] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
_raw_spin_lock_irq+0x17/0x50
[  424.238286] softirqs last  enabled at (512): [<ffffffff81799f7d>]
addrconf_verify_rtnl+0x23d/0x500
[  424.238293] softirqs last disabled at (506): [<ffffffff81799d63>]
addrconf_verify_rtnl+0x23/0x500
[  424.238302] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
 4.2.0-rc2+ #21
[  424.238306] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
BIOS 68TTU Ver. F.04 08/03/2012
[  424.238312] Workqueue: usb_hub_wq hub_event
[  424.238316] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
ffff880218dec000
[  424.238319] RIP: 0010:[<ffffffff813bf2ec>]  [<ffffffff813bf2ec>]
delay_tsc+0x1c/0x50
[  424.238327] RSP: 0018:ffff880218def938  EFLAGS: 00000202
[  424.238330] RAX: 000000004294e518 RBX: 0000000180100008 RCX:
000000004294d8ed
[  424.238333] RDX: 00000000000000ed RSI: 0000000000000002 RDI:
0000000000000001
[  424.238335] RBP: ffff880218def938 R08: 0000000000000001 R09:
0000000000000000
[  424.238338] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff817fe161
[  424.238340] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
ffffffff810d021e
[  424.238344] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
knlGS:0000000000000000
[  424.238347] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  424.238350] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
00000000000407e0
[  424.238352] Stack:
[  424.238354]  ffff880218def948 ffffffff813bf20f ffff880218def978
ffffffff810b428c
[  424.238360]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
ffff880231f1fd40
[  424.238365]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
ffffffff8160f844
[  424.238370] Call Trace:
[  424.238377]  [<ffffffff813bf20f>] __delay+0xf/0x20
[  424.238384]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
[  424.238388]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
[  424.238394]  [<ffffffff8160f70b>] ?
media_device_unregister_entity+0x3b/0x130
[  424.238399]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
[  424.238403]  [<ffffffff8160f70b>]
media_device_unregister_entity+0x3b/0x130
[  424.238407]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
[  424.238416]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
[  424.238421]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
[au0828]
[  424.238427]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
[  424.238431]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
[  424.238436]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
[au0828]
[  424.238441]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
[  424.238446]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
[  424.238453]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
[  424.238457]  [<ffffffff814db175>] device_release_driver+0x25/0x40
[  424.238463]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
[  424.238467]  [<ffffffff814d6df9>] device_del+0x139/0x250
[  424.238472]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
[  424.238476]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
[  424.238480]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
[  424.238484]  [<ffffffff8158e227>] hub_event+0x767/0x1580
[  424.238490]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
[  424.238496]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
[  424.238500]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
[  424.238505]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
[  424.238510]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  424.238514]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
[  424.238518]  [<ffffffff8107e914>] kthread+0xe4/0x100
[  424.238524]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  424.238528]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
[  424.238533]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
[  424.238535] Code: c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f ae f0
0f 31 <48> c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90 65 8b




-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Slow path and cpu lock warnings - MC Next Gen
  2015-11-11 14:22     ` Shuah Khan
@ 2015-11-11 15:36       ` Mauro Carvalho Chehab
  2015-11-11 15:49         ` Shuah Khan
  0 siblings, 1 reply; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2015-11-11 15:36 UTC (permalink / raw)
  To: Shuah Khan; +Cc: Javier Martinez Canillas, Linux Media Mailing List

Em Wed, 11 Nov 2015 07:22:47 -0700
Shuah Khan <shuahkh@osg.samsung.com> escreveu:

> On 11/11/2015 05:30 AM, Mauro Carvalho Chehab wrote:
> > Em Mon, 09 Nov 2015 08:55:06 -0700
> > Shuah Khan <shuahkh@osg.samsung.com> escreveu:
> > 
> >> On 11/09/2015 08:51 AM, Shuah Khan wrote:
> >>> As I mentioned on the IRC, here is the log for the problems I am seeing.
> >>> I have to do eject HVR 950Q TV stick to see the problem.
> >>>
> >>> mc_next_gen.v8.4 branch with no changes.
> >>>
> >>> I can test and debug this week.
> >>>
> >>> thanks,
> >>> -- Shuah
> >>>   
> >>
> >> Forgot to cc linux-media, just in case others are interested
> >> and have ideas on debugging.
> >>
> >> thanks,
> >> -- Shuah
> > 
> >> [    8.558049] ======================================================
> >> [    8.558056] [ INFO: possible circular locking dependency detected ]
> >> [    8.558063] 4.2.0-rc2+ #21 Not tainted
> >> [    8.558070] -------------------------------------------------------
> >> [    8.558077] systemd-udevd/143 is trying to acquire lock:
> >> [    8.558084]  (init_mutex){+.+.+.}, at: [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> >> [    8.558104] 
> >>                but task is already holding lock:
> >> [    8.558114]  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
> >> [    8.558133] 
> >>                which lock already depends on the new lock.
> >>
> >> [    8.558147] 
> >>                the existing dependency chain (in reverse order) is:
> >> [    8.558158] 
> >>                -> #1 (&(&backlight_notifier)->rwsem){++++..}:  
> >> [    8.558170]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> >> [    8.558180]        [<ffffffff817fb006>] down_write+0x36/0x70
> >> [    8.558189]        [<ffffffff8107fdc1>] blocking_notifier_chain_register+0x21/0xb0
> >> [    8.558202]        [<ffffffff81424c98>] backlight_register_notifier+0x18/0x20
> >> [    8.558212]        [<ffffffffa0002019>] acpi_video_get_backlight_type+0xfa/0x163 [video]
> >> [    8.558225]        [<ffffffffa000167e>] acpi_video_bus_add+0x686/0xdfa [video]
> >> [    8.558237]        [<ffffffff814371b0>] acpi_device_probe+0x50/0xf7
> >> [    8.558247]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> >> [    8.558257]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> >> [    8.558266]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> >> [    8.558275]        [<ffffffff814daece>] driver_attach+0x1e/0x20
> >> [    8.558287]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> >> [    8.558296]        [<ffffffff814dc280>] driver_register+0x60/0xe0
> >> [    8.558304]        [<ffffffff81437936>] acpi_bus_register_driver+0x3b/0x43
> >> [    8.558313]        [<ffffffffa0000328>] acpi_video_register+0x6e/0x90 [video]
> >> [    8.558322]        [<ffffffffa000b087>] hid_generic_exit+0x87/0x1000 [hid_generic]
> >> [    8.558334]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> >> [    8.558344]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> >> [    8.558353]        [<ffffffff810f1900>] load_module+0x2170/0x2780
> >> [    8.558363]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> >> [    8.558372]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> >> [    8.558381] 
> >>                -> #0 (init_mutex){+.+.+.}:  
> >> [    8.558392]        [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
> >> [    8.558401]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> >> [    8.558409]        [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
> >> [    8.558417]        [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> >> [    8.558430]        [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
> >> [    8.558442]        [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
> >> [    8.558451]        [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
> >> [    8.558462]        [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
> >> [    8.558474]        [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
> >> [    8.558483]        [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
> >> [    8.558543]        [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
> >> [    8.558585]        [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
> >> [    8.558625]        [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
> >> [    8.558667]        [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
> >> [    8.558706]        [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
> >> [    8.558728]        [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
> >> [    8.558747]        [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
> >> [    8.558783]        [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
> >> [    8.558792]        [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
> >> [    8.558800]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> >> [    8.558809]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> >> [    8.558818]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> >> [    8.558827]        [<ffffffff814daece>] driver_attach+0x1e/0x20
> >> [    8.558835]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> >> [    8.558844]        [<ffffffff814dc280>] driver_register+0x60/0xe0
> >> [    8.558852]        [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
> >> [    8.558860]        [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
> >> [    8.558879]        [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
> >> [    8.558911]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> >> [    8.558920]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> >> [    8.558928]        [<ffffffff810f1900>] load_module+0x2170/0x2780
> >> [    8.558937]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> >> [    8.558945]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> >> [    8.558954] 
> >>                other info that might help us debug this:
> >>
> >> [    8.558968]  Possible unsafe locking scenario:
> >>
> >> [    8.558978]        CPU0                    CPU1
> >> [    8.558984]        ----                    ----
> >> [    8.558989]   lock(&(&backlight_notifier)->rwsem);
> >> [    8.558997]                                lock(init_mutex);
> >> [    8.559004]                                lock(&(&backlight_notifier)->rwsem);
> >> [    8.559015]   lock(init_mutex);
> >> [    8.559021] 
> >>                 *** DEADLOCK ***
> >>
> >> [    8.559035] 4 locks held by systemd-udevd/143:
> >> [    8.559041]  #0:  (&dev->mutex){......}, at: [<ffffffff814db99b>] __driver_attach+0x4b/0xa0
> >> [    8.559056]  #1:  (&dev->mutex){......}, at: [<ffffffff814db9a9>] __driver_attach+0x59/0xa0
> >> [    8.559072]  #2:  (drm_global_mutex){+.+.+.}, at: [<ffffffffa00331f6>] drm_dev_register+0x26/0x100 [drm]
> >> [    8.559097]  #3:  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
> >> [    8.559113] 
> >>                stack backtrace:
> >> [    8.559124] CPU: 2 PID: 143 Comm: systemd-udevd Not tainted 4.2.0-rc2+ #21
> >> [    8.559132] Hardware name: Hewlett-Packard HP ProBook 6475b/180F, BIOS 68TTU Ver. F.04 08/03/2012
> >> [    8.559143]  ffffffff8285ace0 ffff88002b09f378 ffffffff817f4254 ffffffff810c155a
> >> [    8.559156]  ffffffff8285ace0 ffff88002b09f3c8 ffffffff810ac6a3 0000000000000003
> >> [    8.559169]  ffff88002b09f438 ffff88002b09f3c8 ffff88002b06b398 ffff88002b06a600
> >> [    8.559181] Call Trace:
> >> [    8.559190]  [<ffffffff817f4254>] dump_stack+0x45/0x57
> >> [    8.559208]  [<ffffffff810c155a>] ? console_unlock+0x1da/0x580
> >> [    8.559216]  [<ffffffff810ac6a3>] print_circular_bug+0x1e3/0x250
> >> [    8.559225]  [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
> >> [    8.559234]  [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
> >> [    8.559243]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
> >> [    8.559255]  [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
> >> [    8.559264]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
> >> [    8.559277]  [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
> >> [    8.559289]  [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
> >> [    8.559301]  [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
> >> [    8.559310]  [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
> >> [    8.559319]  [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
> >> [    8.559327]  [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
> >> [    8.559374]  [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
> >> [    8.559416]  [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
> >> [    8.559455]  [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
> >> [    8.559481]  [<ffffffffa0038c1b>] ? drm_mode_crtc_set_gamma_size+0x5b/0x70 [drm]
> >> [    8.559523]  [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
> >> [    8.559566]  [<ffffffffa03071d8>] ? radeon_ib_ring_tests+0x58/0xc0 [radeon]
> >> [    8.559601]  [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
> >> [    8.559620]  [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
> >> [    8.559639]  [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
> >> [    8.559674]  [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
> >> [    8.559683]  [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
> >> [    8.559691]  [<ffffffff813f47d0>] ? pci_match_device+0xe0/0x110
> >> [    8.559699]  [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
> >> [    8.559708]  [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
> >> [    8.559717]  [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
> >> [    8.559726]  [<ffffffff814db950>] ? driver_probe_device+0x470/0x470
> >> [    8.559734]  [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
> >> [    8.559743]  [<ffffffff814daece>] driver_attach+0x1e/0x20
> >> [    8.559752]  [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
> >> [    8.559760]  [<ffffffff814dc280>] driver_register+0x60/0xe0
> >> [    8.559767]  [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
> >> [    8.559786]  [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
> >> [    8.559794]  [<ffffffffa039d000>] ? 0xffffffffa039d000
> >> [    8.559825]  [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
> >> [    8.559834]  [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
> >> [    8.559843]  [<ffffffff817f3146>] ? do_init_module+0x28/0x1e9
> >> [    8.559852]  [<ffffffff811c5c3b>] ? kmem_cache_alloc_trace+0xbb/0x160
> >> [    8.559862]  [<ffffffff817f317e>] do_init_module+0x60/0x1e9
> >> [    8.559870]  [<ffffffff810f1900>] load_module+0x2170/0x2780
> >> [    8.559878]  [<ffffffff810edd30>] ? __symbol_put+0x40/0x40
> >> [    8.559888]  [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
> >> [    8.559897]  [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
> > 
> > Sorry, but I fail to see how this is related to the V4L2 subsystem.
> > 
> > At least on my eyes, it seems that the bug is somewhere at the Radeon
> > driver.
> > 
> 
> Mauro,
> 
> I think you didn't look down the dmesg far enough. The following is the
> problem I am talking about and you will see media_device_unregister()
> on the stack. This occurs as soon as the device is removed.

Shuah,

I saw that, but it is clear, from the above log, that the Radeon
driver is broken and it has some bad lock dependencies with the
driver_attach locks. Any other bad lock report related to the
Radeon driver or driver binding/unbiding code are very likely
related to the above bug.

You should either fix the bad lock at the Radeon driver or not
load it at all, in order to be able to get any reliable results
about possible locking troubles with the MC drivers with the Kernel
lock tests.

Regards,
Mauro


> 
> thanks,
> -- Shuah
> 
> [  304.245575] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
> [kworker/2:1:56]
> [  304.245587] Modules linked in: snd_usb_audio snd_usbmidi_lib
> snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
> lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
> ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
> ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
> au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
> nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
> xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
> kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
> ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
> cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
> snd_hda_codec_generic snd_hda_codec_hdmi
> [  304.245661]  snd_hda_intel microcode snd_hda_codec hp_accel
> tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
> input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
> parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
> usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
> drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
> [  304.245709] irq event stamp: 1850
> [  304.245712] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
> _raw_spin_unlock_irq+0x30/0x40
> [  304.245722] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
> _raw_spin_lock_irq+0x17/0x50
> [  304.245727] softirqs last  enabled at (512): [<ffffffff81799f7d>]
> addrconf_verify_rtnl+0x23d/0x500
> [  304.245735] softirqs last disabled at (506): [<ffffffff81799d63>]
> addrconf_verify_rtnl+0x23/0x500
> [  304.245744] CPU: 2 PID: 56 Comm: kworker/2:1 Not tainted 4.2.0-rc2+ #21
> [  304.245747] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
> BIOS 68TTU Ver. F.04 08/03/2012
> [  304.245754] Workqueue: usb_hub_wq hub_event
> [  304.245758] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
> ffff880218dec000
> [  304.245761] RIP: 0010:[<ffffffff813bf2ea>]  [<ffffffff813bf2ea>]
> delay_tsc+0x1a/0x50
> [  304.245769] RSP: 0018:ffff880218def938  EFLAGS: 00000206
> [  304.245772] RAX: 000000001d95bc8c RBX: 0000000180100008 RCX:
> 000000001d95bc8c
> [  304.245775] RDX: 00000000000000ad RSI: 0000000000000002 RDI:
> 0000000000000001
> [  304.245777] RBP: ffff880218def938 R08: 0000000000000001 R09:
> 0000000000000000
> [  304.245780] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff817fe161
> [  304.245783] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
> ffffffff810d021e
> [  304.245786] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
> knlGS:0000000000000000
> [  304.245789] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  304.245792] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
> 00000000000407e0
> [  304.245794] Stack:
> [  304.245796]  ffff880218def948 ffffffff813bf20f ffff880218def978
> ffffffff810b428c
> [  304.245802]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
> ffff880231f1fd40
> [  304.245807]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
> ffffffff8160f844
> [  304.245812] Call Trace:
> [  304.245819]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  304.245826]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  304.245830]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  304.245837]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  304.245841]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  304.245846]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  304.245851]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  304.245859]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  304.245868]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  304.245874]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  304.245878]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  304.245883]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  304.245888]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  304.245893]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  304.245900]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  304.245904]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  304.245910]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  304.245914]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  304.245919]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  304.245923]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  304.245927]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  304.245931]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  304.245937]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  304.245943]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  304.245947]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  304.245952]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  304.245957]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  304.245961]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  304.245965]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  304.245971]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  304.245975]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  304.245980]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  304.245982] Code: 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00
> 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f
> ae f0 <0f> 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90
> [  332.243453] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
> [kworker/2:1:56]
> [  332.243464] Modules linked in: snd_usb_audio snd_usbmidi_lib
> snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
> lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
> ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
> ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
> au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
> nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
> xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
> kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
> ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
> cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
> snd_hda_codec_generic snd_hda_codec_hdmi
> [  332.243542]  snd_hda_intel microcode snd_hda_codec hp_accel
> tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
> input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
> parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
> usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
> drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
> [  332.243592] irq event stamp: 1850
> [  332.243595] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
> _raw_spin_unlock_irq+0x30/0x40
> [  332.243605] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
> _raw_spin_lock_irq+0x17/0x50
> [  332.243612] softirqs last  enabled at (512): [<ffffffff81799f7d>]
> addrconf_verify_rtnl+0x23d/0x500
> [  332.243619] softirqs last disabled at (506): [<ffffffff81799d63>]
> addrconf_verify_rtnl+0x23/0x500
> [  332.243628] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
>  4.2.0-rc2+ #21
> [  332.243632] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
> BIOS 68TTU Ver. F.04 08/03/2012
> [  332.243638] Workqueue: usb_hub_wq hub_event
> [  332.243642] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
> ffff880218dec000
> [  332.243645] RIP: 0010:[<ffffffff813bf2e5>]  [<ffffffff813bf2e5>]
> delay_tsc+0x15/0x50
> [  332.243653] RSP: 0018:ffff880218def938  EFLAGS: 00000202
> [  332.243656] RAX: 0000000015191edb RBX: 0000000180100008 RCX:
> 0000000015191d34
> [  332.243659] RDX: 00000000000000bc RSI: 0000000000000002 RDI:
> 0000000000000001
> [  332.243662] RBP: ffff880218def938 R08: 0000000000000001 R09:
> 0000000000000000
> [  332.243665] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff817fe161
> [  332.243667] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
> ffffffff810d021e
> [  332.243671] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
> knlGS:0000000000000000
> [  332.243674] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  332.243677] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
> 00000000000407e0
> [  332.243679] Stack:
> [  332.243681]  ffff880218def948 ffffffff813bf20f ffff880218def978
> ffffffff810b428c
> [  332.243687]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
> ffff880231f1fd40
> [  332.243692]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
> ffffffff8160f844
> [  332.243697] Call Trace:
> [  332.243704]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  332.243711]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  332.243715]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  332.243721]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  332.243726]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  332.243730]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  332.243734]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  332.243743]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  332.243749]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  332.243754]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  332.243758]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  332.243763]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  332.243768]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  332.243773]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  332.243780]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  332.243784]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  332.243790]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  332.243794]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  332.243799]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  332.243804]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  332.243808]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  332.243812]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  332.243817]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  332.243823]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  332.243827]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  332.243832]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  332.243837]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  332.243841]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  332.243846]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  332.243851]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  332.243855]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  332.243860]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  332.243862] Code: ff 15 68 bb ae 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84
> 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0
> 0f 31 <89> c1 0f ae f0 0f 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39
> [  344.082652] INFO: rcu_sched self-detected stall on CPU { 2}  (t=16250
> jiffies g=16088 c=16087 q=6192)
> [  344.082671] Task dump for CPU 2:
> [  344.082675] kworker/2:1     R  running task        0    56      2
> 0x00000008
> [  344.082686] Workqueue: usb_hub_wq hub_event
> [  344.082689]  0000000000000002 ffff88023ed03d58 ffffffff8108d999
> ffffffff8108d8d1
> [  344.082695]  0000000000000000 0000000000000002 ffffffff81e4ffc0
> ffff88023ed03d78
> [  344.082701]  ffffffff8109089b ffff88023ed16840 0000000000000003
> ffff88023ed03da8
> [  344.082706] Call Trace:
> [  344.082709]  <IRQ>  [<ffffffff8108d999>] sched_show_task+0x129/0x230
> [  344.082721]  [<ffffffff8108d8d1>] ? sched_show_task+0x61/0x230
> [  344.082727]  [<ffffffff8109089b>] dump_cpu_task+0x3b/0x50
> [  344.082733]  [<ffffffff810cd58e>] rcu_dump_cpu_stacks+0x8e/0xe0
> [  344.082738]  [<ffffffff810d0906>] rcu_check_callbacks+0x486/0x770
> [  344.082743]  [<ffffffff810a9580>] ? cpuacct_account_field+0xd0/0x1a0
> [  344.082747]  [<ffffffff810a94b5>] ? cpuacct_account_field+0x5/0x1a0
> [  344.082753]  [<ffffffff810e6212>] ? tick_sched_timer+0x22/0x80
> [  344.082758]  [<ffffffff810e61f0>] ? tick_sched_do_timer+0x30/0x30
> [  344.082762]  [<ffffffff810d5c89>] update_process_times+0x39/0x60
> [  344.082767]  [<ffffffff810e5b25>] tick_sched_handle.isra.16+0x25/0x60
> [  344.082772]  [<ffffffff810e6234>] tick_sched_timer+0x44/0x80
> [  344.082776]  [<ffffffff810d653e>] __hrtimer_run_queues+0xce/0x270
> [  344.082781]  [<ffffffff810d6ceb>] hrtimer_interrupt+0xab/0x1b0
> [  344.082787]  [<ffffffff8103807c>] local_apic_timer_interrupt+0x3c/0x70
> [  344.082792]  [<ffffffff81800031>] smp_apic_timer_interrupt+0x41/0x60
> [  344.082796]  [<ffffffff817fe40d>] apic_timer_interrupt+0x6d/0x80
> [  344.082799]  <EOI>  [<ffffffff813bf2e3>] ? delay_tsc+0x13/0x50
> [  344.082808]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  344.082812]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  344.082816]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  344.082821]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  344.082825]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  344.082829]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  344.082833]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  344.082841]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  344.082846]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  344.082851]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  344.082854]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  344.082860]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  344.082865]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  344.082869]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  344.082875]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  344.082880]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  344.082885]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  344.082889]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  344.082894]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  344.082898]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  344.082902]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  344.082906]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  344.082911]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  344.082917]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  344.082921]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  344.082926]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  344.082931]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  344.082935]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  344.082939]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  344.082944]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  344.082949]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  344.082953]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  368.241164] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s!
> [kworker/2:1:56]
> [  368.241173] Modules linked in: snd_usb_audio snd_usbmidi_lib
> snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
> lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
> ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
> ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
> au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
> nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
> xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
> kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
> ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
> cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
> snd_hda_codec_generic snd_hda_codec_hdmi
> [  368.241251]  snd_hda_intel microcode snd_hda_codec hp_accel
> tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
> input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
> parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
> usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
> drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
> [  368.241300] irq event stamp: 1850
> [  368.241303] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
> _raw_spin_unlock_irq+0x30/0x40
> [  368.241313] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
> _raw_spin_lock_irq+0x17/0x50
> [  368.241318] softirqs last  enabled at (512): [<ffffffff81799f7d>]
> addrconf_verify_rtnl+0x23d/0x500
> [  368.241326] softirqs last disabled at (506): [<ffffffff81799d63>]
> addrconf_verify_rtnl+0x23/0x500
> [  368.241335] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
>  4.2.0-rc2+ #21
> [  368.241339] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
> BIOS 68TTU Ver. F.04 08/03/2012
> [  368.241345] Workqueue: usb_hub_wq hub_event
> [  368.241349] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
> ffff880218dec000
> [  368.241352] RIP: 0010:[<ffffffff813bf2ea>]  [<ffffffff813bf2ea>]
> delay_tsc+0x1a/0x50
> [  368.241359] RSP: 0018:ffff880218def938  EFLAGS: 00000206
> [  368.241363] RAX: 000000005363a164 RBX: 0000000180100008 RCX:
> 000000005363a164
> [  368.241365] RDX: 00000000000000cf RSI: 0000000000000002 RDI:
> 0000000000000001
> [  368.241368] RBP: ffff880218def938 R08: 0000000000000001 R09:
> 0000000000000000
> [  368.241370] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff817fe161
> [  368.241373] R13: ffffffff810d021e R14: ffff880218def8c8 R15:
> 0140000000000000
> [  368.241377] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
> knlGS:0000000000000000
> [  368.241379] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  368.241382] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
> 00000000000407e0
> [  368.241384] Stack:
> [  368.241387]  ffff880218def948 ffffffff813bf20f ffff880218def978
> ffffffff810b428c
> [  368.241392]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
> ffff880231f1fd40
> [  368.241398]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
> ffffffff8160f844
> [  368.241403] Call Trace:
> [  368.241410]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  368.241416]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  368.241421]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  368.241427]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  368.241431]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  368.241436]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  368.241440]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  368.241449]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  368.241454]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  368.241460]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  368.241464]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  368.241469]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  368.241474]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  368.241479]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  368.241486]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  368.241491]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  368.241496]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  368.241501]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  368.241505]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  368.241510]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  368.241514]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  368.241518]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  368.241523]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  368.241529]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  368.241534]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  368.241539]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  368.241544]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  368.241548]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  368.241552]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  368.241558]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  368.241562]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  368.241567]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  368.241569] Code: 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00
> 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f
> ae f0 <0f> 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90
> [  396.239591] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 23s!
> [kworker/2:1:56]
> [  396.239601] Modules linked in: snd_usb_audio snd_usbmidi_lib
> snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
> lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
> ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
> ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
> au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
> nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
> xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
> kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
> ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
> cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
> snd_hda_codec_generic snd_hda_codec_hdmi
> [  396.239676]  snd_hda_intel microcode snd_hda_codec hp_accel
> tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
> input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
> parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
> usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
> drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
> [  396.239724] irq event stamp: 1850
> [  396.239727] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
> _raw_spin_unlock_irq+0x30/0x40
> [  396.239736] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
> _raw_spin_lock_irq+0x17/0x50
> [  396.239742] softirqs last  enabled at (512): [<ffffffff81799f7d>]
> addrconf_verify_rtnl+0x23d/0x500
> [  396.239749] softirqs last disabled at (506): [<ffffffff81799d63>]
> addrconf_verify_rtnl+0x23/0x500
> [  396.239758] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
>  4.2.0-rc2+ #21
> [  396.239761] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
> BIOS 68TTU Ver. F.04 08/03/2012
> [  396.239768] Workqueue: usb_hub_wq hub_event
> [  396.239772] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
> ffff880218dec000
> [  396.239775] RIP: 0010:[<ffffffff813bf2e5>]  [<ffffffff813bf2e5>]
> delay_tsc+0x15/0x50
> [  396.239782] RSP: 0018:ffff880218def938  EFLAGS: 00000206
> [  396.239785] RAX: 000000004afa4fa4 RBX: 0000000180100008 RCX:
> 000000004afa42a6
> [  396.239788] RDX: 00000000000000de RSI: 0000000000000002 RDI:
> 0000000000000001
> [  396.239791] RBP: ffff880218def938 R08: 0000000000000001 R09:
> 0000000000000000
> [  396.239793] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff817fe161
> [  396.239796] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
> ffffffff810d021e
> [  396.239799] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
> knlGS:0000000000000000
> [  396.239802] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  396.239805] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
> 00000000000407e0
> [  396.239807] Stack:
> [  396.239809]  ffff880218def948 ffffffff813bf20f ffff880218def978
> ffffffff810b428c
> [  396.239815]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
> ffff880231f1fd40
> [  396.239820]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
> ffffffff8160f844
> [  396.239825] Call Trace:
> [  396.239833]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  396.239839]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  396.239844]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  396.239850]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  396.239855]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  396.239859]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  396.239864]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  396.239872]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  396.239878]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  396.239883]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  396.239887]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  396.239892]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  396.239898]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  396.239902]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  396.239909]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  396.239914]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  396.239919]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  396.239924]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  396.239929]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  396.239933]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  396.239937]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  396.239941]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  396.239946]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  396.239953]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  396.239957]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  396.239962]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  396.239967]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  396.239971]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  396.239976]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  396.239981]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  396.239986]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  396.239990]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  396.239992] Code: ff 15 68 bb ae 00 5d c3 0f 1f 40 00 66 2e 0f 1f 84
> 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0
> 0f 31 <89> c1 0f ae f0 0f 31 48 c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39
> [  424.238131] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 23s!
> [kworker/2:1:56]
> [  424.238143] Modules linked in: snd_usb_audio snd_usbmidi_lib
> snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi ir_lirc_codec
> lirc_dev ir_sony_decoder ir_xmp_decoder ir_sharp_decoder
> ir_sanyo_decoder ir_mce_kbd_decoder snd_seq_device ir_jvc_decoder
> ir_rc5_decoder ir_rc6_decoder ir_nec_decoder au8522_dig tuner
> au8522_decoder au8522_common au0828 tveeprom nf_conntrack_ipv4
> nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4
> xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter ip_tables x_tables binfmt_misc nls_iso8859_1
> kvm_amd kvm uvcvideo videobuf2_vmalloc videobuf2_memops
> ghash_clmulni_intel videobuf2_core aesni_intel aes_x86_64 ablk_helper
> cryptd lrw hp_wmi gf128mul sparse_keymap snd_hda_codec_idt glue_helper
> snd_hda_codec_generic snd_hda_codec_hdmi
> [  424.238218]  snd_hda_intel microcode snd_hda_codec hp_accel
> tpm_infineon snd_hda_core joydev k10temp serio_raw lis3lv02d snd_hwdep
> input_polldev snd_pcm tpm_tis snd_timer i2c_piix4 shpchp mac_hid
> parport_pc ppdev lp parport autofs4 pl2303 usbserial hid_generic radeon
> usbhid psmouse i2c_algo_bit hid firewire_ohci ttm firewire_core
> drm_kms_helper sdhci_pci crc_itu_t r8169 sdhci mii drm wmi video
> [  424.238267] irq event stamp: 1850
> [  424.238270] hardirqs last  enabled at (1849): [<ffffffff817fce50>]
> _raw_spin_unlock_irq+0x30/0x40
> [  424.238280] hardirqs last disabled at (1850): [<ffffffff817fcbe7>]
> _raw_spin_lock_irq+0x17/0x50
> [  424.238286] softirqs last  enabled at (512): [<ffffffff81799f7d>]
> addrconf_verify_rtnl+0x23d/0x500
> [  424.238293] softirqs last disabled at (506): [<ffffffff81799d63>]
> addrconf_verify_rtnl+0x23/0x500
> [  424.238302] CPU: 2 PID: 56 Comm: kworker/2:1 Tainted: G             L
>  4.2.0-rc2+ #21
> [  424.238306] Hardware name: Hewlett-Packard HP ProBook 6475b/180F,
> BIOS 68TTU Ver. F.04 08/03/2012
> [  424.238312] Workqueue: usb_hub_wq hub_event
> [  424.238316] task: ffff88021e222600 ti: ffff880218dec000 task.ti:
> ffff880218dec000
> [  424.238319] RIP: 0010:[<ffffffff813bf2ec>]  [<ffffffff813bf2ec>]
> delay_tsc+0x1c/0x50
> [  424.238327] RSP: 0018:ffff880218def938  EFLAGS: 00000202
> [  424.238330] RAX: 000000004294e518 RBX: 0000000180100008 RCX:
> 000000004294d8ed
> [  424.238333] RDX: 00000000000000ed RSI: 0000000000000002 RDI:
> 0000000000000001
> [  424.238335] RBP: ffff880218def938 R08: 0000000000000001 R09:
> 0000000000000000
> [  424.238338] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff817fe161
> [  424.238340] R13: ffffffff810d021e R14: ffffffff817fe161 R15:
> ffffffff810d021e
> [  424.238344] FS:  00007fde9af5e940(0000) GS:ffff88023ed00000(0000)
> knlGS:0000000000000000
> [  424.238347] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  424.238350] CR2: 00007f21c0f55000 CR3: 0000000001e0b000 CR4:
> 00000000000407e0
> [  424.238352] Stack:
> [  424.238354]  ffff880218def948 ffffffff813bf20f ffff880218def978
> ffffffff810b428c
> [  424.238360]  ffff88008ced0d70 ffff88008ced0d70 ffff880231f1f800
> ffff880231f1fd40
> [  424.238365]  ffff880218def9a8 ffffffff817fca99 ffffffff8160f70b
> ffffffff8160f844
> [  424.238370] Call Trace:
> [  424.238377]  [<ffffffff813bf20f>] __delay+0xf/0x20
> [  424.238384]  [<ffffffff810b428c>] do_raw_spin_lock+0x8c/0x150
> [  424.238388]  [<ffffffff817fca99>] _raw_spin_lock+0x39/0x40
> [  424.238394]  [<ffffffff8160f70b>] ?
> media_device_unregister_entity+0x3b/0x130
> [  424.238399]  [<ffffffff8160f844>] ? media_device_unregister+0x44/0x120
> [  424.238403]  [<ffffffff8160f70b>]
> media_device_unregister_entity+0x3b/0x130
> [  424.238407]  [<ffffffff8160f8ba>] media_device_unregister+0xba/0x120
> [  424.238416]  [<ffffffffa05d2072>] au0828_usb_release+0x22/0x50 [au0828]
> [  424.238421]  [<ffffffffa05d21fa>] au0828_usb_v4l2_release+0x6a/0x80
> [au0828]
> [  424.238427]  [<ffffffff816180eb>] v4l2_device_release+0x1b/0x20
> [  424.238431]  [<ffffffff816187f5>] v4l2_device_put+0x25/0x30
> [  424.238436]  [<ffffffffa05d2164>] au0828_usb_disconnect+0xc4/0xf0
> [au0828]
> [  424.238441]  [<ffffffff81598bf6>] usb_unbind_interface+0x86/0x270
> [  424.238446]  [<ffffffff810add7d>] ? trace_hardirqs_on+0xd/0x10
> [  424.238453]  [<ffffffff814db0a1>] __device_release_driver+0xa1/0x150
> [  424.238457]  [<ffffffff814db175>] device_release_driver+0x25/0x40
> [  424.238463]  [<ffffffff814da7dc>] bus_remove_device+0x11c/0x1a0
> [  424.238467]  [<ffffffff814d6df9>] device_del+0x139/0x250
> [  424.238472]  [<ffffffff81595de1>] ? remove_intf_ep_devs+0x41/0x60
> [  424.238476]  [<ffffffff81596459>] usb_disable_device+0x89/0x270
> [  424.238480]  [<ffffffff8158be94>] usb_disconnect+0x94/0x2b0
> [  424.238484]  [<ffffffff8158e227>] hub_event+0x767/0x1580
> [  424.238490]  [<ffffffff81087762>] ? finish_task_switch+0x52/0x1e0
> [  424.238496]  [<ffffffff8107826f>] process_one_work+0x1cf/0x540
> [  424.238500]  [<ffffffff81078203>] ? process_one_work+0x163/0x540
> [  424.238505]  [<ffffffff81078628>] worker_thread+0x48/0x4a0
> [  424.238510]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  424.238514]  [<ffffffff810785e0>] ? process_one_work+0x540/0x540
> [  424.238518]  [<ffffffff8107e914>] kthread+0xe4/0x100
> [  424.238524]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  424.238528]  [<ffffffff817fd9cf>] ret_from_fork+0x3f/0x70
> [  424.238533]  [<ffffffff8107e830>] ? kthread_create_on_node+0x220/0x220
> [  424.238535] Code: c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
> 44 00 00 55 48 89 e5 65 8b 35 90 ae c4 7e 0f ae f0 0f 31 89 c1 0f ae f0
> 0f 31 <48> c1 e2 20 89 c0 48 09 c2 89 d0 29 ca 39 d7 76 1c f3 90 65 8b
> 
> 
> 
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Slow path and cpu lock warnings - MC Next Gen
  2015-11-11 15:36       ` Mauro Carvalho Chehab
@ 2015-11-11 15:49         ` Shuah Khan
  2015-11-12  0:25           ` Shuah Khan
  0 siblings, 1 reply; 6+ messages in thread
From: Shuah Khan @ 2015-11-11 15:49 UTC (permalink / raw)
  To: Mauro Carvalho Chehab
  Cc: Javier Martinez Canillas, Linux Media Mailing List, Shuah Khan

On 11/11/2015 08:36 AM, Mauro Carvalho Chehab wrote:
> Em Wed, 11 Nov 2015 07:22:47 -0700
> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
> 
>> On 11/11/2015 05:30 AM, Mauro Carvalho Chehab wrote:
>>> Em Mon, 09 Nov 2015 08:55:06 -0700
>>> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
>>>
>>>> On 11/09/2015 08:51 AM, Shuah Khan wrote:
>>>>> As I mentioned on the IRC, here is the log for the problems I am seeing.
>>>>> I have to do eject HVR 950Q TV stick to see the problem.
>>>>>
>>>>> mc_next_gen.v8.4 branch with no changes.
>>>>>
>>>>> I can test and debug this week.
>>>>>
>>>>> thanks,
>>>>> -- Shuah
>>>>>   
>>>>
>>>> Forgot to cc linux-media, just in case others are interested
>>>> and have ideas on debugging.
>>>>
>>>> thanks,
>>>> -- Shuah
>>>
>>>> [    8.558049] ======================================================
>>>> [    8.558056] [ INFO: possible circular locking dependency detected ]
>>>> [    8.558063] 4.2.0-rc2+ #21 Not tainted
>>>> [    8.558070] -------------------------------------------------------
>>>> [    8.558077] systemd-udevd/143 is trying to acquire lock:
>>>> [    8.558084]  (init_mutex){+.+.+.}, at: [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>>>> [    8.558104] 
>>>>                but task is already holding lock:
>>>> [    8.558114]  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
>>>> [    8.558133] 
>>>>                which lock already depends on the new lock.
>>>>
>>>> [    8.558147] 
>>>>                the existing dependency chain (in reverse order) is:
>>>> [    8.558158] 
>>>>                -> #1 (&(&backlight_notifier)->rwsem){++++..}:  
>>>> [    8.558170]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>>>> [    8.558180]        [<ffffffff817fb006>] down_write+0x36/0x70
>>>> [    8.558189]        [<ffffffff8107fdc1>] blocking_notifier_chain_register+0x21/0xb0
>>>> [    8.558202]        [<ffffffff81424c98>] backlight_register_notifier+0x18/0x20
>>>> [    8.558212]        [<ffffffffa0002019>] acpi_video_get_backlight_type+0xfa/0x163 [video]
>>>> [    8.558225]        [<ffffffffa000167e>] acpi_video_bus_add+0x686/0xdfa [video]
>>>> [    8.558237]        [<ffffffff814371b0>] acpi_device_probe+0x50/0xf7
>>>> [    8.558247]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>>>> [    8.558257]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>>>> [    8.558266]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>>>> [    8.558275]        [<ffffffff814daece>] driver_attach+0x1e/0x20
>>>> [    8.558287]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>>>> [    8.558296]        [<ffffffff814dc280>] driver_register+0x60/0xe0
>>>> [    8.558304]        [<ffffffff81437936>] acpi_bus_register_driver+0x3b/0x43
>>>> [    8.558313]        [<ffffffffa0000328>] acpi_video_register+0x6e/0x90 [video]
>>>> [    8.558322]        [<ffffffffa000b087>] hid_generic_exit+0x87/0x1000 [hid_generic]
>>>> [    8.558334]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>>>> [    8.558344]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>>>> [    8.558353]        [<ffffffff810f1900>] load_module+0x2170/0x2780
>>>> [    8.558363]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>>>> [    8.558372]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
>>>> [    8.558381] 
>>>>                -> #0 (init_mutex){+.+.+.}:  
>>>> [    8.558392]        [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
>>>> [    8.558401]        [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>>>> [    8.558409]        [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
>>>> [    8.558417]        [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>>>> [    8.558430]        [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
>>>> [    8.558442]        [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
>>>> [    8.558451]        [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
>>>> [    8.558462]        [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
>>>> [    8.558474]        [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
>>>> [    8.558483]        [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
>>>> [    8.558543]        [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
>>>> [    8.558585]        [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
>>>> [    8.558625]        [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
>>>> [    8.558667]        [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
>>>> [    8.558706]        [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
>>>> [    8.558728]        [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
>>>> [    8.558747]        [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
>>>> [    8.558783]        [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
>>>> [    8.558792]        [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
>>>> [    8.558800]        [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>>>> [    8.558809]        [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>>>> [    8.558818]        [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>>>> [    8.558827]        [<ffffffff814daece>] driver_attach+0x1e/0x20
>>>> [    8.558835]        [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>>>> [    8.558844]        [<ffffffff814dc280>] driver_register+0x60/0xe0
>>>> [    8.558852]        [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
>>>> [    8.558860]        [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
>>>> [    8.558879]        [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
>>>> [    8.558911]        [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>>>> [    8.558920]        [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>>>> [    8.558928]        [<ffffffff810f1900>] load_module+0x2170/0x2780
>>>> [    8.558937]        [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>>>> [    8.558945]        [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
>>>> [    8.558954] 
>>>>                other info that might help us debug this:
>>>>
>>>> [    8.558968]  Possible unsafe locking scenario:
>>>>
>>>> [    8.558978]        CPU0                    CPU1
>>>> [    8.558984]        ----                    ----
>>>> [    8.558989]   lock(&(&backlight_notifier)->rwsem);
>>>> [    8.558997]                                lock(init_mutex);
>>>> [    8.559004]                                lock(&(&backlight_notifier)->rwsem);
>>>> [    8.559015]   lock(init_mutex);
>>>> [    8.559021] 
>>>>                 *** DEADLOCK ***
>>>>
>>>> [    8.559035] 4 locks held by systemd-udevd/143:
>>>> [    8.559041]  #0:  (&dev->mutex){......}, at: [<ffffffff814db99b>] __driver_attach+0x4b/0xa0
>>>> [    8.559056]  #1:  (&dev->mutex){......}, at: [<ffffffff814db9a9>] __driver_attach+0x59/0xa0
>>>> [    8.559072]  #2:  (drm_global_mutex){+.+.+.}, at: [<ffffffffa00331f6>] drm_dev_register+0x26/0x100 [drm]
>>>> [    8.559097]  #3:  (&(&backlight_notifier)->rwsem){++++..}, at: [<ffffffff8107fc49>] __blocking_notifier_call_chain+0x39/0x70
>>>> [    8.559113] 
>>>>                stack backtrace:
>>>> [    8.559124] CPU: 2 PID: 143 Comm: systemd-udevd Not tainted 4.2.0-rc2+ #21
>>>> [    8.559132] Hardware name: Hewlett-Packard HP ProBook 6475b/180F, BIOS 68TTU Ver. F.04 08/03/2012
>>>> [    8.559143]  ffffffff8285ace0 ffff88002b09f378 ffffffff817f4254 ffffffff810c155a
>>>> [    8.559156]  ffffffff8285ace0 ffff88002b09f3c8 ffffffff810ac6a3 0000000000000003
>>>> [    8.559169]  ffff88002b09f438 ffff88002b09f3c8 ffff88002b06b398 ffff88002b06a600
>>>> [    8.559181] Call Trace:
>>>> [    8.559190]  [<ffffffff817f4254>] dump_stack+0x45/0x57
>>>> [    8.559208]  [<ffffffff810c155a>] ? console_unlock+0x1da/0x580
>>>> [    8.559216]  [<ffffffff810ac6a3>] print_circular_bug+0x1e3/0x250
>>>> [    8.559225]  [<ffffffff810aff59>] __lock_acquire+0x1f29/0x1f90
>>>> [    8.559234]  [<ffffffff810b0c61>] lock_acquire+0xb1/0x130
>>>> [    8.559243]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
>>>> [    8.559255]  [<ffffffff817f9ceb>] mutex_lock_nested+0x4b/0x340
>>>> [    8.559264]  [<ffffffffa0001f36>] ? acpi_video_get_backlight_type+0x17/0x163 [video]
>>>> [    8.559277]  [<ffffffffa0001f36>] acpi_video_get_backlight_type+0x17/0x163 [video]
>>>> [    8.559289]  [<ffffffffa00020ba>] acpi_video_backlight_notify+0x19/0x2f [video]
>>>> [    8.559301]  [<ffffffff8107faad>] notifier_call_chain+0x5d/0x80
>>>> [    8.559310]  [<ffffffff8107fc61>] __blocking_notifier_call_chain+0x51/0x70
>>>> [    8.559319]  [<ffffffff8107fc96>] blocking_notifier_call_chain+0x16/0x20
>>>> [    8.559327]  [<ffffffff81424ff2>] backlight_device_register+0x1a2/0x260
>>>> [    8.559374]  [<ffffffffa02af70a>] radeon_atom_backlight_init+0xda/0x1d0 [radeon]
>>>> [    8.559416]  [<ffffffffa0254713>] radeon_link_encoder_connector+0xc3/0x130 [radeon]
>>>> [    8.559455]  [<ffffffffa0232b06>] radeon_get_atom_connector_info_from_object_table+0x3a6/0x950 [radeon]
>>>> [    8.559481]  [<ffffffffa0038c1b>] ? drm_mode_crtc_set_gamma_size+0x5b/0x70 [drm]
>>>> [    8.559523]  [<ffffffffa0257e4c>] radeon_modeset_init+0x5dc/0xa40 [radeon]
>>>> [    8.559566]  [<ffffffffa03071d8>] ? radeon_ib_ring_tests+0x58/0xc0 [radeon]
>>>> [    8.559601]  [<ffffffffa0230b0b>] radeon_driver_load_kms+0x12b/0x220 [radeon]
>>>> [    8.559620]  [<ffffffffa0033281>] drm_dev_register+0xb1/0x100 [drm]
>>>> [    8.559639]  [<ffffffffa003605d>] drm_get_pci_dev+0x8d/0x1e0 [drm]
>>>> [    8.559674]  [<ffffffffa022c404>] radeon_pci_probe+0xa4/0xc0 [radeon]
>>>> [    8.559683]  [<ffffffff813f3715>] local_pci_probe+0x45/0xa0
>>>> [    8.559691]  [<ffffffff813f47d0>] ? pci_match_device+0xe0/0x110
>>>> [    8.559699]  [<ffffffff813f4911>] pci_device_probe+0xd1/0x120
>>>> [    8.559708]  [<ffffffff814db62d>] driver_probe_device+0x14d/0x470
>>>> [    8.559717]  [<ffffffff814db9e4>] __driver_attach+0x94/0xa0
>>>> [    8.559726]  [<ffffffff814db950>] ? driver_probe_device+0x470/0x470
>>>> [    8.559734]  [<ffffffff814d9366>] bus_for_each_dev+0x66/0xa0
>>>> [    8.559743]  [<ffffffff814daece>] driver_attach+0x1e/0x20
>>>> [    8.559752]  [<ffffffff814daa4e>] bus_add_driver+0x1ee/0x280
>>>> [    8.559760]  [<ffffffff814dc280>] driver_register+0x60/0xe0
>>>> [    8.559767]  [<ffffffff813f2fd4>] __pci_register_driver+0x64/0x70
>>>> [    8.559786]  [<ffffffffa0036290>] drm_pci_init+0xe0/0x110 [drm]
>>>> [    8.559794]  [<ffffffffa039d000>] ? 0xffffffffa039d000
>>>> [    8.559825]  [<ffffffffa039d09d>] radeon_init+0x9d/0xb2 [radeon]
>>>> [    8.559834]  [<ffffffff810002eb>] do_one_initcall+0xab/0x1d0
>>>> [    8.559843]  [<ffffffff817f3146>] ? do_init_module+0x28/0x1e9
>>>> [    8.559852]  [<ffffffff811c5c3b>] ? kmem_cache_alloc_trace+0xbb/0x160
>>>> [    8.559862]  [<ffffffff817f317e>] do_init_module+0x60/0x1e9
>>>> [    8.559870]  [<ffffffff810f1900>] load_module+0x2170/0x2780
>>>> [    8.559878]  [<ffffffff810edd30>] ? __symbol_put+0x40/0x40
>>>> [    8.559888]  [<ffffffff810f212a>] SyS_finit_module+0x9a/0xc0
>>>> [    8.559897]  [<ffffffff817fd5d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
>>>
>>> Sorry, but I fail to see how this is related to the V4L2 subsystem.
>>>
>>> At least on my eyes, it seems that the bug is somewhere at the Radeon
>>> driver.
>>>
>>
>> Mauro,
>>
>> I think you didn't look down the dmesg far enough. The following is the
>> problem I am talking about and you will see media_device_unregister()
>> on the stack. This occurs as soon as the device is removed.
> 
> Shuah,
> 
> I saw that, but it is clear, from the above log, that the Radeon
> driver is broken and it has some bad lock dependencies with the
> driver_attach locks. Any other bad lock report related to the
> Radeon driver or driver binding/unbiding code are very likely
> related to the above bug.
> 
> You should either fix the bad lock at the Radeon driver or not
> load it at all, in order to be able to get any reliable results
> about possible locking troubles with the MC drivers with the Kernel
> lock tests.
> 

Yeah Radeon driver bug could be making things worse. Did you see
any problems with device removal during your testing?

ok found the following commit that fixes the problem:
7231ed1a813e0a9d249bbbe58e66ca058aee83e1

This went into 4.2-rc4 or rc5. I will test applying just this
one patch to mc_next_gen.v8.4 branch and see if device removal
problem also goes away.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Slow path and cpu lock warnings - MC Next Gen
  2015-11-11 15:49         ` Shuah Khan
@ 2015-11-12  0:25           ` Shuah Khan
  2015-11-12  3:25             ` Shuah Khan
  0 siblings, 1 reply; 6+ messages in thread
From: Shuah Khan @ 2015-11-12  0:25 UTC (permalink / raw)
  To: Mauro Carvalho Chehab
  Cc: Javier Martinez Canillas, Linux Media Mailing List, Shuah Khan

On 11/11/2015 08:49 AM, Shuah Khan wrote:
> On 11/11/2015 08:36 AM, Mauro Carvalho Chehab wrote:
>> Em Wed, 11 Nov 2015 07:22:47 -0700
>> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
>>
>>> On 11/11/2015 05:30 AM, Mauro Carvalho Chehab wrote:
>>>> Em Mon, 09 Nov 2015 08:55:06 -0700
>>>> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
>>>>
>>>>> On 11/09/2015 08:51 AM, Shuah Khan wrote:
>>>>>> As I mentioned on the IRC, here is the log for the problems I am seeing.
>>>>>> I have to do eject HVR 950Q TV stick to see the problem.
>>>>>>
>>>>>> mc_next_gen.v8.4 branch with no changes.
>>>>>>
>>>>>> I can test and debug this week.
>>>>>>
>>>>>> thanks,
>>>>>> -- Shuah
>>>>>>   
>>>>>
>>>>> Forgot to cc linux-media, just in case others are interested
>>>>> and have ideas on debugging.
>>>>>

snip

>>>>
>>>> Sorry, but I fail to see how this is related to the V4L2 subsystem.
>>>>
>>>> At least on my eyes, it seems that the bug is somewhere at the Radeon
>>>> driver.
>>>>
>>>
>>> Mauro,
>>>
>>> I think you didn't look down the dmesg far enough. The following is the
>>> problem I am talking about and you will see media_device_unregister()
>>> on the stack. This occurs as soon as the device is removed.
>>
>> Shuah,
>>
>> I saw that, but it is clear, from the above log, that the Radeon
>> driver is broken and it has some bad lock dependencies with the
>> driver_attach locks. Any other bad lock report related to the
>> Radeon driver or driver binding/unbiding code are very likely
>> related to the above bug.
>>
>> You should either fix the bad lock at the Radeon driver or not
>> load it at all, in order to be able to get any reliable results
>> about possible locking troubles with the MC drivers with the Kernel
>> lock tests.
>>
> 
> Yeah Radeon driver bug could be making things worse. Did you see
> any problems with device removal during your testing?
> 
> ok found the following commit that fixes the problem:
> 7231ed1a813e0a9d249bbbe58e66ca058aee83e1
> 
> This went into 4.2-rc4 or rc5. I will test applying just this
> one patch to mc_next_gen.v8.4 branch and see if device removal
> problem also goes away.
> 

Applied the acpi backlight fix and now kernel hangs solid when
device is removed. I managed to get stack trace enabling sysrq
and that showed media_device_unregister_entity() attempt to hold
spin_lock() -> raw_spin_lock() on the stack trace. It is same as
the one seen in the dmesg I sent.

I think we have several calls to media_device_unregister_entity()
from various media core drivers (dvb, v4l2, bridge driver) during
device removal from their unregister paths. This adds lot of
contention on the mdev->lock.

media_device_unregister() calls media_device_unregister_entity()
as well on all the mdev entities.

I am not testing with my ALSA patches at the moment. When that
gets added, media_devnode_is_registered() check to ensure only
one of them (bridge driver or snd-usb-audio) runs
media_device_unregister() won't work as the MEDIA_FLAG_REGISTERED
flag gets cleared towards the end of media_device_unregister().
media_device_unregister() needs to be safe to be run by these two
drivers and still do the work only once. media_device_unregister()
does a lot (removes interface links, interfaces, and then then
unregister entities before it removes the media device devnode
file and call media_devnode_unregister() to clear the
MEDIA_FLAG_REGISTERED bit.

I see two problems to solve:

- ensure media_device_unregister() is safe to be called by one
  or more drivers during device removal (usb disconnect in this
  case)
- Reduce contention on mdev->lock during device removal

I have some ideas on how to do this. I can work on them and send
patches. Sounds like a plan?

thanks,
-- Shuah





-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Slow path and cpu lock warnings - MC Next Gen
  2015-11-12  0:25           ` Shuah Khan
@ 2015-11-12  3:25             ` Shuah Khan
  0 siblings, 0 replies; 6+ messages in thread
From: Shuah Khan @ 2015-11-12  3:25 UTC (permalink / raw)
  To: Mauro Carvalho Chehab
  Cc: Javier Martinez Canillas, Linux Media Mailing List, Shuah Khan

On 11/11/2015 05:25 PM, Shuah Khan wrote:
> On 11/11/2015 08:49 AM, Shuah Khan wrote:
>> On 11/11/2015 08:36 AM, Mauro Carvalho Chehab wrote:
>>> Em Wed, 11 Nov 2015 07:22:47 -0700
>>> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
>>>
>>>> On 11/11/2015 05:30 AM, Mauro Carvalho Chehab wrote:
>>>>> Em Mon, 09 Nov 2015 08:55:06 -0700
>>>>> Shuah Khan <shuahkh@osg.samsung.com> escreveu:
>>>>>
>>>>>> On 11/09/2015 08:51 AM, Shuah Khan wrote:
>>>>>>> As I mentioned on the IRC, here is the log for the problems I am seeing.
>>>>>>> I have to do eject HVR 950Q TV stick to see the problem.
>>>>>>>
>>>>>>> mc_next_gen.v8.4 branch with no changes.
>>>>>>>
>>>>>>> I can test and debug this week.
>>>>>>>
>>>>>>> thanks,
>>>>>>> -- Shuah
>>>>>>>   
>>>>>>
>>>>>> Forgot to cc linux-media, just in case others are interested
>>>>>> and have ideas on debugging.
>>>>>>
> 
> snip
> 
>>>>>
>>>>> Sorry, but I fail to see how this is related to the V4L2 subsystem.
>>>>>
>>>>> At least on my eyes, it seems that the bug is somewhere at the Radeon
>>>>> driver.
>>>>>
>>>>
>>>> Mauro,
>>>>
>>>> I think you didn't look down the dmesg far enough. The following is the
>>>> problem I am talking about and you will see media_device_unregister()
>>>> on the stack. This occurs as soon as the device is removed.
>>>
>>> Shuah,
>>>
>>> I saw that, but it is clear, from the above log, that the Radeon
>>> driver is broken and it has some bad lock dependencies with the
>>> driver_attach locks. Any other bad lock report related to the
>>> Radeon driver or driver binding/unbiding code are very likely
>>> related to the above bug.
>>>
>>> You should either fix the bad lock at the Radeon driver or not
>>> load it at all, in order to be able to get any reliable results
>>> about possible locking troubles with the MC drivers with the Kernel
>>> lock tests.
>>>
>>
>> Yeah Radeon driver bug could be making things worse. Did you see
>> any problems with device removal during your testing?
>>
>> ok found the following commit that fixes the problem:
>> 7231ed1a813e0a9d249bbbe58e66ca058aee83e1
>>
>> This went into 4.2-rc4 or rc5. I will test applying just this
>> one patch to mc_next_gen.v8.4 branch and see if device removal
>> problem also goes away.
>>
> 
> Applied the acpi backlight fix and now kernel hangs solid when
> device is removed. I managed to get stack trace enabling sysrq
> and that showed media_device_unregister_entity() attempt to hold
> spin_lock() -> raw_spin_lock() on the stack trace. It is same as
> the one seen in the dmesg I sent.
> 
> I think we have several calls to media_device_unregister_entity()
> from various media core drivers (dvb, v4l2, bridge driver) during
> device removal from their unregister paths. This adds lot of
> contention on the mdev->lock.
> 
> media_device_unregister() calls media_device_unregister_entity()
> as well on all the mdev entities.
> 
> I am not testing with my ALSA patches at the moment. When that
> gets added, media_devnode_is_registered() check to ensure only
> one of them (bridge driver or snd-usb-audio) runs
> media_device_unregister() won't work as the MEDIA_FLAG_REGISTERED
> flag gets cleared towards the end of media_device_unregister().
> media_device_unregister() needs to be safe to be run by these two
> drivers and still do the work only once. media_device_unregister()
> does a lot (removes interface links, interfaces, and then then
> unregister entities before it removes the media device devnode
> file and call media_devnode_unregister() to clear the
> MEDIA_FLAG_REGISTERED bit.
> 
> I see two problems to solve:
> 
> - ensure media_device_unregister() is safe to be called by one
>   or more drivers during device removal (usb disconnect in this
>   case)
> - Reduce contention on mdev->lock during device removal
> 
> I have some ideas on how to do this. I can work on them and send
> patches. Sounds like a plan?
> 

Found a two line fix to the problem. Will send patch tomorrow.
I was able to do device inserts and removals in a row with the
change. It hangs every time device removed without the change.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-11-12  3:25 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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     [not found] ` <5640C1DA.7040100@osg.samsung.com>
2015-11-11 12:30   ` Slow path and cpu lock warnings - MC Next Gen Mauro Carvalho Chehab
2015-11-11 14:22     ` Shuah Khan
2015-11-11 15:36       ` Mauro Carvalho Chehab
2015-11-11 15:49         ` Shuah Khan
2015-11-12  0:25           ` Shuah Khan
2015-11-12  3:25             ` Shuah Khan

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