When unloading the i915 module (and its dependencies), and then reloading it with disable_display=1, we got the following backtrace:

<6> [261.528723] Console: switching to colour dummy device 80x25
<6> [261.531780] [IGT] drv_module_reload: executing
<6> [261.554480] [IGT] drv_module_reload: starting subtest basic-no-display
<4> [261.660870] general protection fault: 0000 [#1] PREEMPT SMP PTI
<4> [261.660894] CPU: 1 PID: 419 Comm: kworker/1:3 Tainted: G     U            4.19.0-rc6-CI-CI_DRM_4915+ #1
<4> [261.660913] Hardware name: Dell Inc.                 OptiPlex 745                 /0GW726, BIOS 2.3.1  05/21/2007
<4> [261.660947] Workqueue: events process_unsol_events [snd_hda_core]
<4> [261.660969] RIP: 0010:input_handle_event+0xb0/0x570
<4> [261.660982] Code: 00 2f 00 48 8b 93 58 01 00 00 8b 52 08 89 50 04 8b 83 28 07 00 00 48 8b 93 30 07 00 00 8d 70 01 48 8d 04 c2 89 b3 28 07 00 00 <66> 89 28 66 44 89 60 02 44 89 68 04 8b 93 28 07 00 00 83 e1 08 0f
<4> [261.661017] RSP: 0018:ffffc90000343da8 EFLAGS: 00010046
<4> [261.661031] RAX: 6b6b6b6ec6c6c6c3 RBX: ffff8800377be678 RCX: 0000000000000001
<4> [261.661047] RDX: 000000006b6b6b6b RSI: 000000006b6b6b6c RDI: ffffffff82247460
<4> [261.661062] RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000001
<4> [261.661078] R10: 00000000c6980c00 R11: 0000000000000000 R12: 0000000000000004
<4> [261.661094] R13: 0000000000000000 R14: ffff8800377be880 R15: 0000000000000293
<4> [261.661110] FS:  0000000000000000(0000) GS:ffff88003e040000(0000) knlGS:0000000000000000
<4> [261.661128] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [261.661141] CR2: 0000560494672090 CR3: 000000003a4bc000 CR4: 00000000000006e0
<4> [261.661156] Call Trace:
<4> [261.661169]  input_event+0x45/0x70
<4> [261.661185]  snd_jack_report+0xdc/0x100
<4> [261.661213]  snd_hda_jack_report_sync+0x77/0x90 [snd_hda_codec]
<4> [261.661235]  process_unsol_events+0x5d/0x70 [snd_hda_core]
<4> [261.661252]  process_one_work+0x245/0x610
<4> [261.661269]  worker_thread+0x37/0x380
<4> [261.661282]  ? process_one_work+0x610/0x610
<4> [261.661295]  kthread+0x119/0x130
<4> [261.661306]  ? kthread_park+0x80/0x80
<4> [261.661320]  ret_from_fork+0x3a/0x50
<4> [261.661335] Modules linked in: snd_hda_intel i915 vgem coretemp snd_hda_codec_analog snd_hda_codec_generic snd_hda_codec snd_hwdep tg3 lpc_ich snd_hda_core snd_pcm prime_numbers [last unloaded: i915]
<0> [261.661399] Dumping ftrace buffer:
<0> [261.661410] ---------------------------------
<0> [261.661440] CPU:0 [LOST 692807 EVENTS]\x0akms_pipe-1292    0.... 220603027us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.661479] kms_pipe-1295    0.... 222802144us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661512] kms_pipe-1295    0.... 223632109us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661544] kms_pipe-1295    0.... 223632114us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661576] kms_pipe-1295    0.... 223632115us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.661605] kms_pipe-1296    0.... 223927813us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661637] kms_pipe-1296    0.... 224031269us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661669] kms_pipe-1296    0.... 224031274us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661701] kms_pipe-1296    0.... 224031276us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.661729] kms_pipe-1297    0.... 224295646us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661761] kms_pipe-1297    0.... 224295651us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661794] kms_pipe-1297    0.... 224295653us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.661822] kms_pipe-1298    0.... 224427968us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.661854]  rtcwake-1302    0.... 225381332us : 0xffffffffa01443a0: 
<0> [261.661876]  rtcwake-1302    0.... 225381365us : 0xffffffffa011b120: awake?=no
<0> [261.661901]  rtcwake-1302    0.... 225381369us : 0xffffffffa013c770: flags=13 (locked), timeout=9223372036854775807 (forever)
<0> [261.661933] kworker/-1310    0.... 225605001us : 0xffffffffa016a000: 
<0> [261.661956] kworker/-1310    0.... 225605006us : 0xffffffffa0178def: rcs0 request global=0, current=0
<0> [261.661984] kworker/-1324    0.... 225643138us : 0xffffffffa0144960: 
<0> [261.662005] kworker/-1324    0.... 225645677us : 0xffffffffa011b120: awake?=no
<0> [261.662030] kworker/-1324    0.... 225645679us : 0xffffffffa011b1e2: emit barrier on rcs0
<0> [261.662056] kworker/-1324    0.... 225645680us : 0xffffffffa01381c0: 
<0> [261.662078] kworker/-1324    0.... 225646263us : 0xffffffffa0154100: rcs0 fence 4:340992
<0> [261.662104] kworker/-1324    0.... 225646290us : 0xffffffffa01546a9: marking rcs0 as active
<0> [261.662132] kworker/-1324    0d..1 225646319us : 0xffffffffa0153310: rcs0 fence 4:340992 -> global=1, current 0
<0> [261.662162] kms_pipe-1298    0.... 226575791us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662194] kms_pipe-1298    0.... 226575803us : 0xffffffffa01526b0: rcs0 fence 4:340992, global=1, current 1
<0> [261.662223] kms_pipe-1298    0.N.. 226575804us : 0xffffffffa0152c6c: marking rcs0 as inactive
<0> [261.662251] kms_pipe-1298    0.... 226576051us : 0xffffffffa0152943: __retire_engine_request(rcs0) fence 4:340992, global=1, current 1
<0> [261.662284] kms_pipe-1298    0.... 226576056us : 0xffffffffa01380f0: 
<0> [261.662307] kms_pipe-1298    0.... 226576086us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662339] kms_pipe-1298    0.... 226576093us : 0xffffffffa015241c: rcs0 seqno 1 (current 1) -> 0
<0> [261.662366] kworker/-64      0.... 226576134us : 0xffffffffa011b120: awake?=yes
<0> [261.662391] kworker/-64      0.... 226576136us : 0xffffffffa0136f27: active_requests=0 (after switch-to-kernel-context)
<0> [261.662422] kworker/-64      0.... 226576145us : 0xffffffffa0136140: 
<0> [261.662443]  rtcwake-1345    0.... 227867888us : 0xffffffffa01443a0: 
<0> [261.662465]  rtcwake-1345    0.... 227867898us : 0xffffffffa011b120: awake?=no
<0> [261.662490]  rtcwake-1345    0.... 227867903us : 0xffffffffa013c770: flags=13 (locked), timeout=9223372036854775807 (forever)
<0> [261.662522] kworker/-1315    0.... 228149137us : 0xffffffffa0144960: 
<0> [261.662543] kworker/-1315    0.... 228151538us : 0xffffffffa011b120: awake?=no
<0> [261.662568] kworker/-1315    0.... 228151540us : 0xffffffffa011b1e2: emit barrier on rcs0
<0> [261.662593] kworker/-1315    0.... 228151542us : 0xffffffffa01381c0: 
<0> [261.662615] kworker/-1315    0.... 228151600us : 0xffffffffa0154100: rcs0 fence 4:340993
<0> [261.662641] kworker/-1315    0.... 228151603us : 0xffffffffa01546a9: marking rcs0 as active
<0> [261.662668] kworker/-1315    0d..1 228151610us : 0xffffffffa0153310: rcs0 fence 4:340993 -> global=1, current 0
<0> [261.662699] kms_pipe-1339    0.... 229085754us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662731] kms_pipe-1339    0.... 229085766us : 0xffffffffa01526b0: rcs0 fence 4:340993, global=1, current 1
<0> [261.662760] kms_pipe-1339    0.... 229085767us : 0xffffffffa0152c6c: marking rcs0 as inactive
<0> [261.662788] kms_pipe-1339    0.... 229085769us : 0xffffffffa0152943: __retire_engine_request(rcs0) fence 4:340993, global=1, current 1
<0> [261.662821] kms_pipe-1339    0.... 229085774us : 0xffffffffa01380f0: 
<0> [261.662843] kms_pipe-1339    0.... 229085803us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662875] kms_pipe-1339    0.... 229085809us : 0xffffffffa015241c: rcs0 seqno 1 (current 1) -> 0
<0> [261.662904] kms_pipe-1356    0.... 229618755us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662936] kms_pipe-1356    0.... 229618760us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.662968] kms_pipe-1356    0.... 229618762us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.662996]  kms_psr-1360    0.... 230128774us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663028]  kms_psr-1360    0.... 230130460us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663060]  kms_psr-1360    0.... 230130465us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663092]  kms_psr-1360    0.... 230130466us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663120] kms_setm-1362    0.... 230395717us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663152] kms_setm-1362    0.... 230397325us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663184] kms_setm-1362    0.... 230397330us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663216] kms_setm-1362    0.... 230397331us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663244]   pm_rps-1384    0.... 253425790us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663276]   pm_rps-1384    0.... 253426339us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663307]   pm_rps-1384    0.... 253426341us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663335]   pm_rps-1384    0.... 253427006us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663367]   pm_rps-1384    0.... 253427011us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663398]   pm_rps-1384    0.... 253427012us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663428] CPU:1 [LOST 1001609 EVENTS]\x0aprime_bu-1386    1.... 253719147us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663468] prime_bu-1386    1.... 253719152us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663500] prime_bu-1386    1.... 253719154us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663528] prime_bu-1387    0.... 253865128us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663559] prime_bu-1387    0.... 253866138us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663591] prime_bu-1387    0.... 253866141us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663618] prime_bu-1387    0.... 253870429us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663650] prime_bu-1387    0.... 253870434us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663682] prime_bu-1387    0.... 253870435us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663710] prime_bu-1388    0.... 254015829us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663741] prime_bu-1388    0.... 254016400us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663773] prime_bu-1388    0.... 254016402us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663800] prime_bu-1388    0.... 254021472us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663833] prime_bu-1388    0.... 254021479us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663864] prime_bu-1388    0.... 254021480us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.663892] prime_se-1389    1.... 254181265us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663924] prime_se-1389    1.... 254182570us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663956] prime_se-1389    1.... 254182575us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.663987] prime_se-1389    1.... 254182577us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664015] prime_se-1390    1.... 254330449us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664047] prime_se-1390    1.... 254333330us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664078] prime_se-1390    1.... 254333336us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664110] prime_se-1390    1.... 254333337us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664138] prime_se-1391    0.... 254480430us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664169] prime_se-1391    0.... 254491386us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664201] prime_se-1391    0.... 254491391us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664233] prime_se-1391    0.... 254491392us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664261] prime_se-1392    1.... 254647757us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664292] prime_se-1392    1.... 254668292us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664324] prime_se-1392    1.... 254668297us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664356] prime_se-1392    1.... 254668299us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664384] prime_se-1393    1.... 254809287us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664415] prime_se-1393    1.... 254810301us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664447] prime_se-1393    1.... 254810305us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664479] prime_se-1393    1.... 254810306us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664507] prime_se-1394    0.... 254965188us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664538] prime_se-1394    0.... 254976072us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664570] prime_se-1394    0.... 254976076us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664601] prime_se-1394    0.... 254976078us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664629] prime_vg-1395    0.... 255139146us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664661] prime_vg-1395    0.... 255139667us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664693] prime_vg-1395    0.... 255139669us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664720] prime_vg-1395    0.... 255141546us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664752] prime_vg-1395    0.... 255141552us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664784] prime_vg-1395    0.... 255141554us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664811] prime_vg-1396    0.... 255305442us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664843] prime_vg-1396    0.... 255306040us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664875] prime_vg-1396    0.... 255306043us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664902] prime_vg-1396    0.... 255913519us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664934] prime_vg-1396    0.... 255913526us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.664965] prime_vg-1396    0.... 255913528us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.664993] prime_vg-1399    1.... 256256848us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665025] prime_vg-1399    1.... 256257404us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665057] prime_vg-1399    1.... 256257407us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665084] prime_vg-1399    1.... 256300584us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665116] prime_vg-1399    1.... 256300591us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665148] prime_vg-1399    1.... 256300593us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665176] prime_vg-1401    1.... 256456494us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665207] prime_vg-1401    1.... 256457107us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665239] prime_vg-1401    1.... 256457109us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665267] prime_vg-1401    1.... 256519184us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665298] prime_vg-1401    1.... 256519190us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665330] prime_vg-1401    1.... 256519191us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665357] prime_vg-1403    1.... 256672679us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665389] prime_vg-1403    1.... 256673261us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665421] prime_vg-1403    1.... 256673263us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665448] prime_vg-1403    1.... 256675810us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665480] prime_vg-1403    1.... 256675817us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665512] prime_vg-1403    1.... 256675819us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665540] prime_vg-1404    0.... 256839073us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665571] prime_vg-1404    0.... 256839585us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665603] prime_vg-1404    0.... 256839587us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665630] prime_vg-1404    0.... 256866805us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665662] prime_vg-1404    0.... 256866810us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665693] prime_vg-1404    0.... 256866811us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665721] prime_vg-1405    1.... 257038615us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665753] prime_vg-1405    1.... 257039174us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665784] prime_vg-1405    1.... 257039177us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665812] prime_vg-1405    1.... 257070464us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665843] prime_vg-1405    1.... 257070469us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665875] prime_vg-1405    1.... 257070471us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665903] prime_vg-1406    1.... 257238228us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665935] prime_vg-1406    1.... 257238738us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.665966] prime_vg-1406    1.... 257238741us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.665994] prime_vg-1406    1.... 257240172us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666025] prime_vg-1406    1.... 257240177us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666057] prime_vg-1406    1.... 257240178us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666084] prime_vg-1407    0.... 257404551us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666116] prime_vg-1407    0.... 257405138us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666148] prime_vg-1407    0.... 257405140us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666176] prime_vg-1407    1.N.. 257407726us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666208] prime_vg-1407    1.... 257407822us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666239] prime_vg-1407    1.... 257407824us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666267] prime_vg-1408    0.... 257570811us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666299] prime_vg-1408    0.... 257571389us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666330] prime_vg-1408    0.... 257571391us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666358] prime_vg-1408    0.... 257604802us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666390] prime_vg-1408    0.... 257604807us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666421] prime_vg-1408    0.... 257604809us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666449] vgem_bas-1412    1.... 258219856us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666481] vgem_bas-1412    1.... 258221821us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666513] vgem_bas-1412    1.... 258221828us : 0xffffffffa013c770: flags=3 (locked), timeout=9223372036854775807 (forever)
<0> [261.666544] vgem_bas-1412    1.... 258221830us : 0xffffffffa015241c: rcs0 seqno 0 (current 0) -> 0
<0> [261.666572] drv_modu-1430    0.... 259807132us : 0xffffffffa01443a0: 
<0> [261.666594] drv_modu-1430    0.... 259807141us : 0xffffffffa011b120: awake?=no
<0> [261.666618] drv_modu-1430    0.... 259807145us : 0xffffffffa013c770: flags=13 (locked), timeout=9223372036854775807 (forever)
<0> [261.666649] drv_modu-1430    0.... 259876581us : 0xffffffffa01442e0: 
<0> [261.666810] drv_modu-1430    1.... 260466336us : i915_gem_sanitize: 
<0> [261.666898] drv_modu-1430    1.... 260677738us : i915_gem_unpark: 
<0> [261.666982] drv_modu-1430    1.... 260677834us : i915_request_add: rcs0 fence 16:1
<0> [261.667070] drv_modu-1430    1.... 260678432us : i915_request_add: marking rcs0 as active
<0> [261.667160] drv_modu-1430    1d..1 260678527us : __i915_request_submit: rcs0 fence 16:1 -> global=1, current 0
<0> [261.667245] drv_modu-1430    1.... 260678906us : i915_gem_switch_to_kernel_context: awake?=yes
<0> [261.667335] drv_modu-1430    1.... 260678909us : i915_request_retire: rcs0 fence 16:1, global=1, current 1
<0> [261.667426] drv_modu-1430    1.... 260678911us : i915_request_retire: marking rcs0 as inactive
<0> [261.667521] drv_modu-1430    1.... 260678913us : i915_request_retire: __retire_engine_request(rcs0) fence 16:1, global=1, current 1
<0> [261.667613] drv_modu-1430    1.... 260679062us : i915_gem_park: 
<0> [261.667690] drv_modu-1430    1.... 260679186us : i915_gem_switch_to_kernel_context: emit barrier on rcs0
<0> [261.667780] drv_modu-1430    1.... 260679188us : i915_gem_unpark: 
<0> [261.667865] drv_modu-1430    1.... 260679210us : i915_request_add: rcs0 fence 16:2
<0> [261.667955] drv_modu-1430    1.... 260679213us : i915_request_add: marking rcs0 as active
<0> [261.668045] drv_modu-1430    1d..1 260679219us : __i915_request_submit: rcs0 fence 16:2 -> global=2, current 1
<0> [261.668135] drv_modu-1430    1.... 260679229us : i915_gem_wait_for_idle: flags=2 (locked), timeout=200
<0> [261.668232] drv_modu-1430    1.... 260679239us : i915_request_retire: rcs0 fence 16:2, global=2, current 2
<0> [261.668330] drv_modu-1430    1.... 260679240us : i915_request_retire: marking rcs0 as inactive
<0> [261.668425] drv_modu-1430    1.... 260679242us : i915_request_retire: __retire_engine_request(rcs0) fence 16:2, global=2, current 2
<0> [261.668526] drv_modu-1430    1.... 260679247us : i915_gem_park: 
<0> [261.668613] drv_modu-1430    1.... 260679266us : __i915_gem_park: 
<0> [261.668630] ---------------------------------
<4> [261.668646] ---[ end trace ca4429c0a621143b ]---
<4> [261.668664] RIP: 0010:input_handle_event+0xb0/0x570
<4> [261.668678] Code: 00 2f 00 48 8b 93 58 01 00 00 8b 52 08 89 50 04 8b 83 28 07 00 00 48 8b 93 30 07 00 00 8d 70 01 48 8d 04 c2 89 b3 28 07 00 00 <66> 89 28 66 44 89 60 02 44 89 68 04 8b 93 28 07 00 00 83 e1 08 0f
<4> [261.668714] RSP: 0018:ffffc90000343da8 EFLAGS: 00010046
<4> [261.668729] RAX: 6b6b6b6ec6c6c6c3 RBX: ffff8800377be678 RCX: 0000000000000001
<4> [261.668745] RDX: 000000006b6b6b6b RSI: 000000006b6b6b6c RDI: ffffffff82247460
<4> [261.668760] RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000001
<4> [261.668776] R10: 00000000c6980c00 R11: 0000000000000000 R12: 0000000000000004
<4> [261.668792] R13: 0000000000000000 R14: ffff8800377be880 R15: 0000000000000293
<4> [261.668808] FS:  0000000000000000(0000) GS:ffff88003e040000(0000) knlGS:0000000000000000
<4> [261.668826] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [261.668840] CR2: 0000560494672090 CR3: 000000003a4bc000 CR4: 00000000000006e0
<3> [261.668857] BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:34
<3> [261.668878] in_atomic(): 1, irqs_disabled(): 1, pid: 419, name: kworker/1:3
<4> [261.668893] INFO: lockdep is turned off.
<4> [261.668903] irq event stamp: 116856
<4> [261.668917] hardirqs last  enabled at (116855): [<ffffffff81940a94>] _raw_spin_unlock_irq+0x24/0x50
<4> [261.668938] hardirqs last disabled at (116856): [<ffffffff819408cd>] _raw_spin_lock_irqsave+0xd/0x50
<4> [261.668961] softirqs last  enabled at (116572): [<ffffffff81c0031d>] __do_softirq+0x31d/0x483
<4> [261.668983] softirqs last disabled at (116449): [<ffffffff8108c519>] irq_exit+0xa9/0xc0
<3> [261.669001] Preemption disabled at:
<4> [261.669003] [<0000000000000000>]           (null)
<4> [261.669026] CPU: 1 PID: 419 Comm: kworker/1:3 Tainted: G     UD           4.19.0-rc6-CI-CI_DRM_4915+ #1
<4> [261.669047] Hardware name: Dell Inc.                 OptiPlex 745                 /0GW726, BIOS 2.3.1  05/21/2007
<4> [261.669077] Workqueue: events process_unsol_events [snd_hda_core]
<4> [261.669094] Call Trace:
<4> [261.669106]  dump_stack+0x67/0x9b
<4> [261.669119]  ___might_sleep+0x167/0x250
<4> [261.669133]  exit_signals+0x2b/0x2d0
<4> [261.669145]  do_exit+0xa3/0xd00
<4> [261.669159]  ? process_one_work+0x610/0x610
<4> [261.669171]  ? kthread+0x119/0x130
<4> [261.669184]  rewind_stack_do_exit+0x17/0x20
<6> [261.669258] note: kworker/1:3[419] exited with preempt_count 1

The test is part of IGT (https://cgit.freedesktop.org/drm/igt-gpu-tools/tree/tests/drv_module_reload.c#n346). You may also want to check out how the sound drivers are being unloaded: https://cgit.freedesktop.org/drm/igt-gpu-tools/tree/lib/igt_kmod.c#n317

Full logs: https://intel-gfx-ci.01.org/tree/drm-tip/IGT_4662/fi-bwr-2160/igt@drv_module_reload@basic-no-display.html