<4> [221.014558] 
-> #0 (debugfs:i915_lpsp_capability#2){++++}-{0:0}:
<4> [221.014614]        drm_debugfs_connector_remove+0x19/0x30
<4> [221.014624]        drm_connector_unregister+0x8b/0xb0
<4> [221.014633]        drm_connector_unregister_all+0x52/0x90
<4> [221.014642]        drm_modeset_unregister_all+0xd/0x30
<4> [221.014651]        drm_dev_unregister+0x4f/0xa0
<4> [221.014658]        drm_dev_unplug+0x23/0x40
<4> [221.014665]        i915_driver_remove+0x95/0x100 [i915]
<4> [221.015083]        i915_pci_remove+0x19/0x30 [i915]
<4> [221.015587] Chain exists of:
  debugfs:i915_lpsp_capability#2 --> &of->mutex --> &sb->s_type->i_mutex_key#2

<4> [221.015658]   lock(debugfs:i915_lpsp_capability#2);
<4> [221.015739]  #3: ffffffff827cbbc0 (drm_connector_list_iter){.+.+}-{0:0}, ...
<4> [221.015758]  #4: ffff8881113890d0 (&connector->mutex){+.+.}-{3:3}, at: dr...
<4> [221.015966]  drm_debugfs_connector_remove+0x19/0x30
...

<6> [559.949775] Console: switching to colour dummy device 80x25
<6> [559.950840] [IGT] gem_exec_suspend: executing
<7> [559.974705] i915 0000:00:02.0: [drm:i915_gem_open [i915]] 
<7> [559.976018] i915 0000:00:02.0: [drm:i915_drop_caches_set [i915]] Dropping...
<7> [559.976668] i915 0000:00:02.0: [drm:i915_gem_open [i915]] 
<7> [559.977579] i915 0000:00:02.0: [drm:i915_gem_open [i915]] 
<6> [559.990639] [IGT] gem_exec_suspend: starting subtest basic-S3
<6> [559.991720] [IGT] gem_exec_suspend: starting dynamic subtest smem
<7> [559.995816] i915 0000:00:02.0: [drm:i915_drop_caches_set [i915]] Dropping...
<7> [560.755531] i915 0000:00:02.0: [drm:i915_drop_caches_set [i915]] Dropping...
<7> [560.768209] i915 0000:00:02.0: [drm:i915_drop_caches_set [i915]] Dropping...
<6> [561.651556] PM: suspend entry (deep)
<6> [561.660373] Filesystems sync: 0.008 seconds
<6> [561.661274] Freezing user space processes
<3> [577.384818] Freezing user space processes aborted after 15.723 seconds (1...
<6> [577.384862] task:systemd-journal state:D stack:12344 pid:109   ppid:1    ...
<6> [577.384885] Call Trace:
...