Re: [Intel-gfx] [PATCH] drm/i915: fix blank screen booting crashes

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 04/10/2021 08:36, Jani Nikula wrote:
> On Fri, 24 Sep 2021, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
>> On Tue, Sep 21, 2021 at 06:50:39PM -0700, Matthew Brost wrote:
>>> From: Hugh Dickins <hughd@google.com>
>>>
>>> 5.15-rc1 crashes with blank screen when booting up on two ThinkPads
>>> using i915.  Bisections converge convincingly, but arrive at different
>>> and surprising "culprits", none of them the actual culprit.
>>>
>>> netconsole (with init_netconsole() hacked to call i915_init() when
>>> logging has started, instead of by module_init()) tells the story:
>>>
>>> kernel BUG at drivers/gpu/drm/i915/i915_sw_fence.c:245!
>>> with RSI: ffffffff814d408b pointing to sw_fence_dummy_notify().
>>> I've been building with CONFIG_CC_OPTIMIZE_FOR_SIZE=y, and that
>>> function needs to be 4-byte aligned.
>>>
>>> v2:
>>>   (Jani Nikula)
>>>    - Change BUG_ON to WARN_ON
>>> v3:
>>>   (Jani / Tvrtko)
>>>    - Short circuit __i915_sw_fence_init on WARN_ON
>>> v4:
>>>   (Lucas)
>>>    - Break WARN_ON changes out in a different patch
>>>
>>> Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation")
>>> Signed-off-by: Hugh Dickins <hughd@google.com>
>>> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>>> Reviewed-by: Matthew Brost <matthew.brost@intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/gt/intel_context.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
>>> index ff637147b1a9..e7f78bc7ebfc 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_context.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_context.c
>>> @@ -362,8 +362,8 @@ static int __intel_context_active(struct i915_active *active)
>>>   	return 0;
>>>   }
>>>   
>>> -static int sw_fence_dummy_notify(struct i915_sw_fence *sf,
>>> -				 enum i915_sw_fence_notify state)
>>> +static int __i915_sw_fence_call
>>> +sw_fence_dummy_notify(struct i915_sw_fence *sf, enum i915_sw_fence_notify state)
>>>   {
>>>   	return NOTIFY_DONE;
>>>   }
>>
>> This thing seems broken beyond just this alignment stuff. I'm getting
>> this spew from DEBUG_OBJECTS all the time on a glk here:
> 
> Nobody followed through with this, so:
> 
> https://lore.kernel.org/r/20211002020257.34a0e882@oasis.local.home
> 
> and
> 
> cdc1e6e225e3 ("drm/i915: fix blank screen booting crashes")

John you pushed this yesterday? Will this cause a problem now if we have 
two commits for the same bug:

commit b0179f0d18dd7e6fb6b1c52c49ac21365257e97e
Author:     Hugh Dickins <hughd@google.com>
AuthorDate: Tue Sep 21 18:50:39 2021 -0700
Commit:     John Harrison <John.C.Harrison@Intel.com>
CommitDate: Thu Oct 14 18:29:01 2021 -0700

     drm/i915: fix blank screen booting crashes



commit cdc1e6e225e3256d56dc6648411630e71d7c776b
Author:     Hugh Dickins <hughd@google.com>
AuthorDate: Sat Oct 2 03:17:29 2021 -0700
Commit:     Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Sat Oct 2 09:39:15 2021 -0700

     drm/i915: fix blank screen booting crashes

Regards,

Tvrtko

> 
> 
> BR,
> Jani.
> 
> 
>>
>> [   48.122629] ------------[ cut here ]------------
>> [   48.122640] ODEBUG: init destroyed (active state 0) object type: i915_sw_fence hint: sw_fence_dummy_notify+0x0/0x10 [i915]
>> [   48.122963] WARNING: CPU: 0 PID: 815 at lib/debugobjects.c:505 debug_print_object+0x6e/0x90
>> [   48.122976] Modules linked in: i915 i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_gtt agpgart fuse nls_iso8859_1 nls_cp437 vfat fat intel_rapl_msr wmi_bmof intel_rapl_common x86_pkg_temp_thermal r8169 realtek mdio_devres coretemp libphy efi_pstore evdev sdhci_pci cqhci sdhci mei_me mmc_core i2c_i801 intel_pmc_core mei led_class wmi i2c_smbus sch_fq_codel drm ip_tables x_tables ipv6 autofs4
>> [   48.123119] CPU: 0 PID: 815 Comm: kms_async_flips Not tainted 5.15.0-rc2-hsw+ #131
>> [   48.123125] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
>> [   48.123129] RIP: 0010:debug_print_object+0x6e/0x90
>> [   48.123137] Code: 07 08 02 83 c0 01 8b 4b 14 4c 8b 45 00 48 c7 c7 a0 19 0a 82 89 05 66 07 08 02 8b 43 10 48 8b 14 c5 c0 0d e4 81 e8 d7 2e 3c 00 <0f> 0b 83 05 c5 c0 0c 01 01 48 83 c4 08 5b 5d c3 83 05 b7 c0 0c 01
>> [   48.123142] RSP: 0018:ffffc90000dabae0 EFLAGS: 00010282
>> [   48.123150] RAX: 0000000000000000 RBX: ffff88810004f848 RCX: 0000000000000000
>> [   48.123154] RDX: 0000000080000001 RSI: ffffffff8112673f RDI: ffffffff8112673f
>> [   48.123159] RBP: ffffffffa0577480 R08: ffff88827fbfcfe8 R09: 000000000009fffb
>> [   48.123163] R10: 00000000fffe0000 R11: 3fffffffffffffff R12: ffff88810a04d100
>> [   48.123167] R13: ffff88810a07d308 R14: ffff888109990800 R15: ffff88810997b800
>> [   48.123171] FS:  00007ffff624b9c0(0000) GS:ffff888276e00000(0000) knlGS:0000000000000000
>> [   48.123176] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   48.123181] CR2: 00007ffff7f93bf0 CR3: 0000000108e56000 CR4: 0000000000350ef0
>> [   48.123185] Call Trace:
>> [   48.123190]  i915_sw_fence_reinit+0x15/0x40 [i915]
>> [   48.123341]  intel_context_init+0x16b/0x1d0 [i915]
>> [   48.123492]  intel_context_create+0x33/0x100 [i915]
>> [   48.123642]  default_engines+0x9d/0x120 [i915]
>> [   48.123806]  i915_gem_create_context+0x465/0x630 [i915]
>> [   48.125964]  ? trace_kmalloc+0x29/0xd0
>> [   48.125976]  ? kmem_cache_alloc_trace+0x121/0x620
>> [   48.125984]  i915_gem_context_open+0x145/0x1d0 [i915]
>> [   48.126172]  i915_gem_open+0x75/0xb0 [i915]
>> [   48.126364]  drm_file_alloc+0x1b1/0x280 [drm]
>> [   48.126427]  drm_open+0xde/0x250 [drm]
>> [   48.126482]  drm_stub_open+0xa8/0x130 [drm]
>> [   48.126538]  chrdev_open+0xbf/0x240
>> [   48.126547]  ? cdev_device_add+0x90/0x90
>> [   48.126553]  do_dentry_open+0x151/0x3a0
>> [   48.126560]  path_openat+0x76f/0xa10
>> [   48.126568]  do_filp_open+0xa9/0x150
>> [   48.126575]  ? preempt_count_sub+0x9b/0xd0
>> [   48.126584]  ? _raw_spin_unlock+0x29/0x40
>> [   48.126593]  do_sys_openat2+0x97/0x160
>> [   48.126600]  __x64_sys_openat+0x54/0x90
>> [   48.126607]  do_syscall_64+0x38/0x90
>> [   48.126614]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   48.126622] RIP: 0033:0x7ffff7cdca5b
>> [   48.126630] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
>> [   48.126636] RSP: 002b:00007fffffffda20 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>> [   48.126645] RAX: ffffffffffffffda RBX: 00007fffffffdb60 RCX: 00007ffff7cdca5b
>> [   48.126649] RDX: 0000000000000002 RSI: 00007fffffffdb60 RDI: 00000000ffffff9c
>> [   48.126654] RBP: 00007fffffffdb60 R08: 0000000000000001 R09: 000000000000000e
>> [   48.126658] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
>> [   48.126663] R13: 00007ffff7f9406a R14: 0000000000000000 R15: 00000000fffffffb
>> [   48.126669] irq event stamp: 29565
>> [   48.126673] hardirqs last  enabled at (29571): [<ffffffff81126357>] __up_console_sem+0x67/0x70
>> [   48.126682] hardirqs last disabled at (29576): [<ffffffff8112633c>] __up_console_sem+0x4c/0x70
>> [   48.126689] softirqs last  enabled at (29394): [<ffffffff81c0032c>] __do_softirq+0x32c/0x499
>> [   48.126696] softirqs last disabled at (29371): [<ffffffff810ba2ed>] irq_exit_rcu+0xdd/0x130
>> [   48.126704] ---[ end trace 4978f2ce56481e4b ]---
>> [   48.126711] ------------[ cut here ]------------
>> [   48.126714] ODEBUG: activate destroyed (active state 0) object type: i915_sw_fence hint: sw_fence_dummy_notify+0x0/0x10 [i915]
>> [   48.127053] WARNING: CPU: 1 PID: 815 at lib/debugobjects.c:505 debug_print_object+0x6e/0x90
>> [   48.127062] Modules linked in: i915 i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_gtt agpgart fuse nls_iso8859_1 nls_cp437 vfat fat intel_rapl_msr wmi_bmof intel_rapl_common x86_pkg_temp_thermal r8169 realtek mdio_devres coretemp libphy efi_pstore evdev sdhci_pci cqhci sdhci mei_me mmc_core i2c_i801 intel_pmc_core mei led_class wmi i2c_smbus sch_fq_codel drm ip_tables x_tables ipv6 autofs4
>> [   48.127216] CPU: 1 PID: 815 Comm: kms_async_flips Tainted: G        W         5.15.0-rc2-hsw+ #131
>> [   48.127221] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
>> [   48.127226] RIP: 0010:debug_print_object+0x6e/0x90
>> [   48.127232] Code: 07 08 02 83 c0 01 8b 4b 14 4c 8b 45 00 48 c7 c7 a0 19 0a 82 89 05 66 07 08 02 8b 43 10 48 8b 14 c5 c0 0d e4 81 e8 d7 2e 3c 00 <0f> 0b 83 05 c5 c0 0c 01 01 48 83 c4 08 5b 5d c3 83 05 b7 c0 0c 01
>> [   48.127238] RSP: 0018:ffffc90000daba88 EFLAGS: 00010282
>> [   48.127245] RAX: 0000000000000000 RBX: ffff88810004f848 RCX: 0000000000000000
>> [   48.127250] RDX: 0000000080000001 RSI: ffffffff8112673f RDI: ffffffff8112673f
>> [   48.127254] RBP: ffffffffa0577480 R08: ffff88827fbfcfe8 R09: 000000000009fffb
>> [   48.127259] R10: 00000000fffe0000 R11: 3fffffffffffffff R12: ffff88810a04d468
>> [   48.127263] R13: ffffffffa0577480 R14: ffffffff835ce0b8 R15: ffff88810997b800
>> [   48.127268] FS:  00007ffff624b9c0(0000) GS:ffff888276e80000(0000) knlGS:0000000000000000
>> [   48.127273] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   48.127277] CR2: 000055555556f5e8 CR3: 0000000108e56000 CR4: 0000000000350ee0
>> [   48.127282] Call Trace:
>> [   48.127287]  debug_object_activate+0x174/0x200
>> [   48.127296]  i915_sw_fence_commit+0x15/0x20 [i915]
>> [   48.127461]  intel_context_init+0x173/0x1d0 [i915]
>> [   48.127627]  intel_context_create+0x33/0x100 [i915]
>> [   48.127792]  default_engines+0x9d/0x120 [i915]
>> [   48.127971]  i915_gem_create_context+0x465/0x630 [i915]
>> [   48.128195]  ? trace_kmalloc+0x29/0xd0
>> [   48.128203]  ? kmem_cache_alloc_trace+0x121/0x620
>> [   48.128211]  i915_gem_context_open+0x145/0x1d0 [i915]
>> [   48.128389]  i915_gem_open+0x75/0xb0 [i915]
>> [   48.128577]  drm_file_alloc+0x1b1/0x280 [drm]
>> [   48.128632]  drm_open+0xde/0x250 [drm]
>> [   48.128687]  drm_stub_open+0xa8/0x130 [drm]
>> [   48.128742]  chrdev_open+0xbf/0x240
>> [   48.128749]  ? cdev_device_add+0x90/0x90
>> [   48.128754]  do_dentry_open+0x151/0x3a0
>> [   48.128761]  path_openat+0x76f/0xa10
>> [   48.128768]  do_filp_open+0xa9/0x150
>> [   48.128775]  ? preempt_count_sub+0x9b/0xd0
>> [   48.128782]  ? _raw_spin_unlock+0x29/0x40
>> [   48.128789]  do_sys_openat2+0x97/0x160
>> [   48.128795]  __x64_sys_openat+0x54/0x90
>> [   48.128802]  do_syscall_64+0x38/0x90
>> [   48.128808]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   48.128815] RIP: 0033:0x7ffff7cdca5b
>> [   48.128821] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
>> [   48.128826] RSP: 002b:00007fffffffda20 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>> [   48.128835] RAX: ffffffffffffffda RBX: 00007fffffffdb60 RCX: 00007ffff7cdca5b
>> [   48.128839] RDX: 0000000000000002 RSI: 00007fffffffdb60 RDI: 00000000ffffff9c
>> [   48.128844] RBP: 00007fffffffdb60 R08: 0000000000000001 R09: 000000000000000e
>> [   48.128848] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
>> [   48.128852] R13: 00007ffff7f9406a R14: 0000000000000000 R15: 00000000fffffffb
>> [   48.128859] irq event stamp: 30217
>> [   48.128862] hardirqs last  enabled at (30223): [<ffffffff81126357>] __up_console_sem+0x67/0x70
>> [   48.128869] hardirqs last disabled at (30228): [<ffffffff8112633c>] __up_console_sem+0x4c/0x70
>> [   48.128875] softirqs last  enabled at (30050): [<ffffffff81c0032c>] __do_softirq+0x32c/0x499
>> [   48.128881] softirqs last disabled at (30035): [<ffffffff810ba2ed>] irq_exit_rcu+0xdd/0x130
>> [   48.128888] ---[ end trace 4978f2ce56481e4c ]---
>> [   48.128895] ------------[ cut here ]------------
>> [   48.128899] ODEBUG: active_state destroyed (active state 0) object type: i915_sw_fence hint: sw_fence_dummy_notify+0x0/0x10 [i915]
>> [   48.129179] WARNING: CPU: 1 PID: 815 at lib/debugobjects.c:505 debug_print_object+0x6e/0x90
>> [   48.129187] Modules linked in: i915 i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_gtt agpgart fuse nls_iso8859_1 nls_cp437 vfat fat intel_rapl_msr wmi_bmof intel_rapl_common x86_pkg_temp_thermal r8169 realtek mdio_devres coretemp libphy efi_pstore evdev sdhci_pci cqhci sdhci mei_me mmc_core i2c_i801 intel_pmc_core mei led_class wmi i2c_smbus sch_fq_codel drm ip_tables x_tables ipv6 autofs4
>> [   48.129328] CPU: 1 PID: 815 Comm: kms_async_flips Tainted: G        W         5.15.0-rc2-hsw+ #131
>> [   48.129334] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
>> [   48.129338] RIP: 0010:debug_print_object+0x6e/0x90
>> [   48.129344] Code: 07 08 02 83 c0 01 8b 4b 14 4c 8b 45 00 48 c7 c7 a0 19 0a 82 89 05 66 07 08 02 8b 43 10 48 8b 14 c5 c0 0d e4 81 e8 d7 2e 3c 00 <0f> 0b 83 05 c5 c0 0c 01 01 48 83 c4 08 5b 5d c3 83 05 b7 c0 0c 01
>> [   48.129350] RSP: 0018:ffffc90000dabaa8 EFLAGS: 00010286
>> [   48.129357] RAX: 0000000000000000 RBX: ffff88810004f848 RCX: 0000000000000000
>> [   48.129362] RDX: 0000000080000001 RSI: ffffffff8112673f RDI: ffffffff8112673f
>> [   48.129366] RBP: ffffffffa0577480 R08: ffff88827fbfcfe8 R09: 000000000009fffb
>> [   48.129371] R10: 00000000fffe0000 R11: 3fffffffffffffff R12: ffff88810a04d100
>> [   48.129375] R13: ffff88810a07d308 R14: 0000000000000000 R15: ffff88810997b800
>> [   48.129379] FS:  00007ffff624b9c0(0000) GS:ffff888276e80000(0000) knlGS:0000000000000000
>> [   48.129384] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   48.129389] CR2: 000055555556f5e8 CR3: 0000000108e56000 CR4: 0000000000350ee0
>> [   48.129393] Call Trace:
>> [   48.129398]  __i915_sw_fence_complete+0x70/0x240 [i915]
>> [   48.129564]  ? preempt_count_sub+0x9b/0xd0
>> [   48.129572]  intel_context_init+0x173/0x1d0 [i915]
>> [   48.129738]  intel_context_create+0x33/0x100 [i915]
>> [   48.129902]  default_engines+0x9d/0x120 [i915]
>> [   48.130080]  i915_gem_create_context+0x465/0x630 [i915]
>> [   48.130258]  ? trace_kmalloc+0x29/0xd0
>> [   48.130264]  ? kmem_cache_alloc_trace+0x121/0x620
>> [   48.130271]  i915_gem_context_open+0x145/0x1d0 [i915]
>> [   48.130449]  i915_gem_open+0x75/0xb0 [i915]
>> [   48.130635]  drm_file_alloc+0x1b1/0x280 [drm]
>> [   48.130689]  drm_open+0xde/0x250 [drm]
>> [   48.130744]  drm_stub_open+0xa8/0x130 [drm]
>> [   48.130801]  chrdev_open+0xbf/0x240
>> [   48.130807]  ? cdev_device_add+0x90/0x90
>> [   48.130813]  do_dentry_open+0x151/0x3a0
>> [   48.130819]  path_openat+0x76f/0xa10
>> [   48.130826]  do_filp_open+0xa9/0x150
>> [   48.130833]  ? preempt_count_sub+0x9b/0xd0
>> [   48.130839]  ? _raw_spin_unlock+0x29/0x40
>> [   48.130847]  do_sys_openat2+0x97/0x160
>> [   48.130853]  __x64_sys_openat+0x54/0x90
>> [   48.130860]  do_syscall_64+0x38/0x90
>> [   48.130866]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   48.130873] RIP: 0033:0x7ffff7cdca5b
>> [   48.130878] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
>> [   48.130883] RSP: 002b:00007fffffffda20 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>> [   48.130892] RAX: ffffffffffffffda RBX: 00007fffffffdb60 RCX: 00007ffff7cdca5b
>> [   48.130896] RDX: 0000000000000002 RSI: 00007fffffffdb60 RDI: 00000000ffffff9c
>> [   48.130901] RBP: 00007fffffffdb60 R08: 0000000000000001 R09: 000000000000000e
>> [   48.130905] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
>> [   48.130909] R13: 00007ffff7f9406a R14: 0000000000000000 R15: 00000000fffffffb
>> [   48.130916] irq event stamp: 30843
>> [   48.130919] hardirqs last  enabled at (30849): [<ffffffff81126357>] __up_console_sem+0x67/0x70
>> [   48.130926] hardirqs last disabled at (30854): [<ffffffff8112633c>] __up_console_sem+0x4c/0x70
>> [   48.130932] softirqs last  enabled at (30050): [<ffffffff81c0032c>] __do_softirq+0x32c/0x499
>> [   48.130938] softirqs last disabled at (30035): [<ffffffff810ba2ed>] irq_exit_rcu+0xdd/0x130
>> [   48.130944] ---[ end trace 4978f2ce56481e4d ]---
>> [   48.130950] ------------[ cut here ]------------
>> [   48.130954] ODEBUG: active_state destroyed (active state 0) object type: i915_sw_fence hint: sw_fence_dummy_notify+0x0/0x10 [i915]
>> [   48.131232] WARNING: CPU: 1 PID: 815 at lib/debugobjects.c:505 debug_print_object+0x6e/0x90
>> [   48.131240] Modules linked in: i915 i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_gtt agpgart fuse nls_iso8859_1 nls_cp437 vfat fat intel_rapl_msr wmi_bmof intel_rapl_common x86_pkg_temp_thermal r8169 realtek mdio_devres coretemp libphy efi_pstore evdev sdhci_pci cqhci sdhci mei_me mmc_core i2c_i801 intel_pmc_core mei led_class wmi i2c_smbus sch_fq_codel drm ip_tables x_tables ipv6 autofs4
>> [   48.131381] CPU: 1 PID: 815 Comm: kms_async_flips Tainted: G        W         5.15.0-rc2-hsw+ #131
>> [   48.131387] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
>> [   48.131391] RIP: 0010:debug_print_object+0x6e/0x90
>> [   48.131397] Code: 07 08 02 83 c0 01 8b 4b 14 4c 8b 45 00 48 c7 c7 a0 19 0a 82 89 05 66 07 08 02 8b 43 10 48 8b 14 c5 c0 0d e4 81 e8 d7 2e 3c 00 <0f> 0b 83 05 c5 c0 0c 01 01 48 83 c4 08 5b 5d c3 83 05 b7 c0 0c 01
>> [   48.131402] RSP: 0018:ffffc90000dabaa8 EFLAGS: 00010286
>> [   48.131410] RAX: 0000000000000000 RBX: ffff88810004f848 RCX: 0000000000000000
>> [   48.131414] RDX: 0000000080000001 RSI: ffffffff8112673f RDI: ffffffff8112673f
>> [   48.131419] RBP: ffffffffa0577480 R08: ffff88827fbfcfe8 R09: 000000000009fffb
>> [   48.131423] R10: 00000000fffe0000 R11: 3fffffffffffffff R12: ffff88810a04d100
>> [   48.131427] R13: ffff88810a07d308 R14: 0000000000000000 R15: ffff88810997b800
>> [   48.131432] FS:  00007ffff624b9c0(0000) GS:ffff888276e80000(0000) knlGS:0000000000000000
>> [   48.131437] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   48.131441] CR2: 000055555556f5e8 CR3: 0000000108e56000 CR4: 0000000000350ee0
>> [   48.131446] Call Trace:
>> [   48.131450]  __i915_sw_fence_complete+0x9c/0x240 [i915]
>> [   48.131614]  ? preempt_count_sub+0x9b/0xd0
>> [   48.131622]  intel_context_init+0x173/0x1d0 [i915]
>> [   48.131787]  intel_context_create+0x33/0x100 [i915]
>> [   48.131951]  default_engines+0x9d/0x120 [i915]
>> [   48.132129]  i915_gem_create_context+0x465/0x630 [i915]
>> [   48.132306]  ? trace_kmalloc+0x29/0xd0
>> [   48.132313]  ? kmem_cache_alloc_trace+0x121/0x620
>> [   48.132320]  i915_gem_context_open+0x145/0x1d0 [i915]
>> [   48.132498]  i915_gem_open+0x75/0xb0 [i915]
>> [   48.132685]  drm_file_alloc+0x1b1/0x280 [drm]
>> [   48.132739]  drm_open+0xde/0x250 [drm]
>> [   48.132793]  drm_stub_open+0xa8/0x130 [drm]
>> [   48.132849]  chrdev_open+0xbf/0x240
>> [   48.132855]  ? cdev_device_add+0x90/0x90
>> [   48.132861]  do_dentry_open+0x151/0x3a0
>> [   48.132867]  path_openat+0x76f/0xa10
>> [   48.132874]  do_filp_open+0xa9/0x150
>> [   48.132881]  ? preempt_count_sub+0x9b/0xd0
>> [   48.132887]  ? _raw_spin_unlock+0x29/0x40
>> [   48.132895]  do_sys_openat2+0x97/0x160
>> [   48.132901]  __x64_sys_openat+0x54/0x90
>> [   48.132907]  do_syscall_64+0x38/0x90
>> [   48.132914]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   48.132921] RIP: 0033:0x7ffff7cdca5b
>> [   48.132926] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
>> [   48.132931] RSP: 002b:00007fffffffda20 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>> [   48.132939] RAX: ffffffffffffffda RBX: 00007fffffffdb60 RCX: 00007ffff7cdca5b
>> [   48.132944] RDX: 0000000000000002 RSI: 00007fffffffdb60 RDI: 00000000ffffff9c
>> [   48.132948] RBP: 00007fffffffdb60 R08: 0000000000000001 R09: 000000000000000e
>> [   48.132952] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
>> [   48.132956] R13: 00007ffff7f9406a R14: 0000000000000000 R15: 00000000fffffffb
>> [   48.132963] irq event stamp: 31465
>> [   48.132966] hardirqs last  enabled at (31471): [<ffffffff81126357>] __up_console_sem+0x67/0x70
>> [   48.132973] hardirqs last disabled at (31476): [<ffffffff8112633c>] __up_console_sem+0x4c/0x70
>> [   48.132979] softirqs last  enabled at (30050): [<ffffffff81c0032c>] __do_softirq+0x32c/0x499
>> [   48.132984] softirqs last disabled at (30035): [<ffffffff810ba2ed>] irq_exit_rcu+0xdd/0x130
>> [   48.132991] ---[ end trace 4978f2ce56481e4e ]---
>> [   48.132996] ------------[ cut here ]------------
>> [   48.133000] ODEBUG: deactivate destroyed (active state 0) object type: i915_sw_fence hint: sw_fence_dummy_notify+0x0/0x10 [i915]
>> [   48.133277] WARNING: CPU: 1 PID: 815 at lib/debugobjects.c:505 debug_print_object+0x6e/0x90
>> [   48.133284] Modules linked in: i915 i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_gtt agpgart fuse nls_iso8859_1 nls_cp437 vfat fat intel_rapl_msr wmi_bmof intel_rapl_common x86_pkg_temp_thermal r8169 realtek mdio_devres coretemp libphy efi_pstore evdev sdhci_pci cqhci sdhci mei_me mmc_core i2c_i801 intel_pmc_core mei led_class wmi i2c_smbus sch_fq_codel drm ip_tables x_tables ipv6 autofs4
>> [   48.133425] CPU: 1 PID: 815 Comm: kms_async_flips Tainted: G        W         5.15.0-rc2-hsw+ #131
>> [   48.133430] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
>> [   48.133434] RIP: 0010:debug_print_object+0x6e/0x90
>> [   48.133440] Code: 07 08 02 83 c0 01 8b 4b 14 4c 8b 45 00 48 c7 c7 a0 19 0a 82 89 05 66 07 08 02 8b 43 10 48 8b 14 c5 c0 0d e4 81 e8 d7 2e 3c 00 <0f> 0b 83 05 c5 c0 0c 01 01 48 83 c4 08 5b 5d c3 83 05 b7 c0 0c 01
>> [   48.133445] RSP: 0018:ffffc90000dabaa8 EFLAGS: 00010286
>> [   48.133453] RAX: 0000000000000000 RBX: ffff88810004f848 RCX: 0000000000000000
>> [   48.133458] RDX: 0000000080000001 RSI: ffffffff8112673f RDI: ffffffff8112673f
>> [   48.133462] RBP: ffffffffa0577480 R08: ffff88827fbfcfe8 R09: 000000000009fffb
>> [   48.133468] R10: 00000000fffe0000 R11: 3fffffffffffffff R12: ffff88810a04d100
>> [   48.133472] R13: ffff88810a07d308 R14: 0000000000000000 R15: ffff88810997b800
>> [   48.133476] FS:  00007ffff624b9c0(0000) GS:ffff888276e80000(0000) knlGS:0000000000000000
>> [   48.133481] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   48.133486] CR2: 000055555556f5e8 CR3: 0000000108e56000 CR4: 0000000000350ee0
>> [   48.133490] Call Trace:
>> [   48.133495]  __i915_sw_fence_complete+0xab/0x240 [i915]
>> [   48.133658]  ? preempt_count_sub+0x9b/0xd0
>> [   48.133666]  intel_context_init+0x173/0x1d0 [i915]
>> [   48.133830]  intel_context_create+0x33/0x100 [i915]
>> [   48.142705]  default_engines+0x9d/0x120 [i915]
>> [   48.142861]  i915_gem_create_context+0x465/0x630 [i915]
>> [   48.142996]  ? trace_kmalloc+0x29/0xd0
>> [   48.143003]  ? kmem_cache_alloc_trace+0x121/0x620
>> [   48.143009]  i915_gem_context_open+0x145/0x1d0 [i915]
>> [   48.143141]  i915_gem_open+0x75/0xb0 [i915]
>> [   48.143438]  drm_file_alloc+0x1b1/0x280 [drm]
>> [   48.143516]  drm_open+0xde/0x250 [drm]
>> [   48.143557]  drm_stub_open+0xa8/0x130 [drm]
>> [   48.143598]  chrdev_open+0xbf/0x240
>> [   48.143604]  ? cdev_device_add+0x90/0x90
>> [   48.143608]  do_dentry_open+0x151/0x3a0
>> [   48.143614]  path_openat+0x76f/0xa10
>> [   48.143619]  do_filp_open+0xa9/0x150
>> [   48.143625]  ? preempt_count_sub+0x9b/0xd0
>> [   48.143631]  ? _raw_spin_unlock+0x29/0x40
>> [   48.143638]  do_sys_openat2+0x97/0x160
>> [   48.143644]  __x64_sys_openat+0x54/0x90
>> [   48.143648]  do_syscall_64+0x38/0x90
>> [   48.143654]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [   48.143660] RIP: 0033:0x7ffff7cdca5b
>> [   48.143664] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
>> [   48.143668] RSP: 002b:00007fffffffda20 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>> [   48.143675] RAX: ffffffffffffffda RBX: 00007fffffffdb60 RCX: 00007ffff7cdca5b
>> [   48.143679] RDX: 0000000000000002 RSI: 00007fffffffdb60 RDI: 00000000ffffff9c
>> [   48.143682] RBP: 00007fffffffdb60 R08: 0000000000000001 R09: 000000000000000e
>> [   48.143685] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
>> [   48.143688] R13: 00007ffff7f9406a R14: 0000000000000000 R15: 00000000fffffffb
>> [   48.143693] irq event stamp: 32275
>> [   48.143696] hardirqs last  enabled at (32281): [<ffffffff81126357>] __up_console_sem+0x67/0x70
>> [   48.143701] hardirqs last disabled at (32286): [<ffffffff8112633c>] __up_console_sem+0x4c/0x70
>> [   48.143706] softirqs last  enabled at (32138): [<ffffffff81c0032c>] __do_softirq+0x32c/0x499
>> [   48.143710] softirqs last disabled at (32125): [<ffffffff810ba2ed>] irq_exit_rcu+0xdd/0x130
>> [   48.143716] ---[ end trace 4978f2ce56481e4f ]---
>