https://intel-gfx-ci.01.org/tree/drm-tip/drmtip_344/fi-skl-6700k2/igt@kms_flip@2x-flip-vs-absolute-wf_vblank-interruptible.html
<3> [124.194487] INFO: task systemd-udevd:326 blocked for more than 61 seconds.
<3> [124.194498]       Tainted: G     U  W         5.3.0-rc4-g66992026e64f-drmtip_344+ #1
<3> [124.194503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
<6> [124.194508] systemd-udevd   D12592   326    281 0x80004100
<4> [124.194521] Call Trace:
<4> [124.194538]  ? __schedule+0x30e/0x860
<4> [124.194551]  schedule+0x2e/0xb0
<4> [124.194561]  schedule_preempt_disabled+0xf/0x20
<4> [124.194569]  __mutex_lock+0x27c/0x9b0
<4> [124.194586]  ? codec_exec_verb+0x9c/0x100 [snd_hda_codec]
<4> [124.194597]  ? regcache_mark_dirty+0x17/0x40
<4> [124.194610]  ? regcache_mark_dirty+0x17/0x40
<4> [124.194617]  regcache_mark_dirty+0x17/0x40
<4> [124.194632]  hda_call_codec_resume+0x1d/0x130 [snd_hda_codec]
<4> [124.194649]  snd_hda_bus_reset_codecs+0x28/0x70 [snd_hda_codec]
<4> [124.194666]  snd_hda_bus_reset+0x2e/0x40 [snd_hda_codec]
<4> [124.194679]  codec_exec_verb+0xdd/0x100 [snd_hda_codec]
<4> [124.194696]  hda_reg_read+0x88/0x220 [snd_hda_core]
<4> [124.194705]  ? regcache_rbtree_read+0x1f/0x60
<4> [124.194714]  _regmap_read+0x5f/0x1c0
<4> [124.194723]  regmap_read+0x39/0x60
<4> [124.194736]  __snd_hdac_regmap_read_raw+0x29/0xa0 [snd_hda_core]
<4> [124.194752]  query_pcm_param+0xa0/0xc0 [snd_hda_core]
<4> [124.194765]  snd_hdac_query_supported_pcm+0x57/0x270 [snd_hda_core]
<4> [124.194783]  hdmi_parse_codec+0x16a/0x480 [snd_hda_codec_hdmi]
<4> [124.194792]  ? regmap_write+0x4e/0x60
<4> [124.194805]  ? snd_hdac_regmap_write_raw+0x20/0x90 [snd_hda_core]
<4> [124.194821]  parse_intel_hdmi+0xd/0xb0 [snd_hda_codec_hdmi]
<4> [124.194834]  hda_codec_driver_probe+0x89/0x160 [snd_hda_codec]
<4> [124.194842]  ? driver_sysfs_add+0x60/0x90
<4> [124.194850]  really_probe+0xea/0x3d0
<4> [124.194860]  driver_probe_device+0x10b/0x120
<4> [124.194868]  device_driver_attach+0x4a/0x50
<4> [124.194877]  __driver_attach+0x97/0x130
<4> [124.194885]  ? device_driver_attach+0x50/0x50
<4> [124.194892]  bus_for_each_dev+0x74/0xc0
<4> [124.194901]  bus_add_driver+0x13f/0x210
<4> [124.194909]  ? 0xffffffffc03bc000
<4> [124.194916]  driver_register+0x56/0xe0
<4> [124.194923]  ? 0xffffffffc03bc000
<4> [124.194930]  do_one_initcall+0x58/0x300
<4> [124.194940]  ? do_init_module+0x1d/0x1f6
<4> [124.194950]  ? rcu_read_lock_sched_held+0x6f/0x80
<4> [124.194958]  ? kmem_cache_alloc_trace+0x2d1/0x300
<4> [124.194969]  do_init_module+0x56/0x1f6
<4> [124.194978]  load_module+0x25bd/0x2a40
<4> [124.195004]  ? __se_sys_finit_module+0xd3/0xf0
<4> [124.195012]  __se_sys_finit_module+0xd3/0xf0
<4> [124.195028]  do_syscall_64+0x55/0x1c0
<4> [124.195037]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [124.195043] RIP: 0033:0x7fb2dc911839
<4> [124.195056] Code: Bad RIP value.
<4> [124.195062] RSP: 002b:00007ffc7f5511b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
<4> [124.195069] RAX: ffffffffffffffda RBX: 000055b27fadc8b0 RCX: 00007fb2dc911839
<4> [124.195074] RDX: 0000000000000000 RSI: 00007fb2dc5f0145 RDI: 0000000000000007
<4> [124.195079] RBP: 00007fb2dc5f0145 R08: 0000000000000000 R09: 00007ffc7f5512d0
<4> [124.195084] R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
<4> [124.195089] R13: 000055b27fb01b60 R14: 0000000000020000 R15: 000055b27fadc8b0
<4> [124.195118] INFO: lockdep is turned off.
<6> [124.195122]   task                        PC stack   pid father
<6> [124.195129] systemd         S11952     1      0 0x00000000
<4> [124.195139] Call Trace:
<4> [124.195152]  ? __schedule+0x30e/0x860
<4> [124.195164]  ? ep_poll+0x2c4/0x5b0
<4> [124.195173]  schedule+0x2e/0xb0
<4> [124.195181]  schedule_hrtimeout_range_clock+0x13e/0x150
<4> [124.195188]  ? ep_poll+0x4f1/0x5b0
<4> [124.195200]  ? ep_poll+0x2c4/0x5b0
<4> [124.195207]  ep_poll+0x2a4/0x5b0
<4> [124.195222]  ? wake_up_q+0x80/0x80
<4> [124.195234]  do_epoll_wait+0xd2/0xf0
<4> [124.195244]  __x64_sys_epoll_wait+0x15/0x20
<4> [124.195250]  do_syscall_64+0x55/0x1c0
<4> [124.195259]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [124.195264] RIP: 0033:0x7fd10e5cdbb7
<4> [124.195273] Code: Bad RIP value.
<4> [124.195278] RSP: 002b:00007ffe6da69f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e8
<4> [124.195285] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fd10e5cdbb7
<4> [124.195290] RDX: 000000000000003d RSI: 00007ffe6da69fc0 RDI: 0000000000000004
<4> [124.195294] RBP: 00007ffe6da69fc0 R08: 0000000000000000 R09: 7465677261742e79
<4> [124.195300] R10: 00000000ffffffff R11: 0000000000000293 R12: 000000000000003d
<4> [124.195305] R13: 00000000ffffffff R14: 00007ffe6da69fc0 R15: 0000000000000001
<6> [124.195319] kthreadd        S14040     2      0 0x80004000