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AMD WX4150 - Hotplugging on an MST hub doesn't work

Submitted by Lyude Paul @lyudess

Assigned to Default DRI bug account

Link to original bug (#108014)

Description

On the HP Zbook I've got here with an AMD WX4150 GPU, DP MST is entirely nonfunctional. The only part of MST that works is the first modeset. Every single modeset afterwards fails while spamming this in dmesg:

[ 77.797646] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 77.797698] WARNING: CPU: 7 PID: 55 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 77.797698] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 77.797719] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 77.797727] CPU: 7 PID: 55 Comm: kworker/7:0 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 77.797728] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 77.797738] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 77.797766] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 77.797766] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 77.797782] RSP: 0018:ffff9c4f81aeba10 EFLAGS: 00010297
[ 77.797783] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 77.797783] RDX: 0000000000000000 RSI: ffff8ddf2f5d6938 RDI: ffff8ddf2f5d6938
[ 77.797784] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 77.797784] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 77.797785] R13: 0000000000004ea4 R14: 0000000000010000 R15: 0000000000000000
[ 77.797786] FS: 0000000000000000(0000) GS:ffff8ddf2f5c0000(0000) knlGS:0000000000000000
[ 77.797786] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 77.797787] CR2: 00007f2ec5105020 CR3: 000000044820a003 CR4: 00000000003606e0
[ 77.797787] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 77.797788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 77.797788] Call Trace:
[ 77.797820] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 77.797848] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 77.797875] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 77.797902] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 77.797931] ? dce_pipe_control_lock+0x1da/0x1f0 [amdgpu]
[ 77.797976] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 77.798020] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 77.798023] ? _cond_resched+0x15/0x30
[ 77.798024] ? wait_for_completion_timeout+0x3a/0x190
[ 77.798025] ? wait_for_completion_interruptible+0x35/0x1d0
[ 77.798053] ? dm_plane_helper_cleanup_fb+0x120/0x120 [amdgpu]
[ 77.798058] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 77.798062] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 77.798069] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 77.798076] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 77.798079] process_one_work+0x1a1/0x350
[ 77.798080] worker_thread+0x30/0x380
[ 77.798082] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 77.798083] kthread+0x112/0x130
[ 77.798084] ? kthread_create_worker_on_cpu+0x70/0x70
[ 77.798086] ret_from_fork+0x35/0x40
[ 77.798087] ---[ end trace db8425ba857d73a8 ]---
[ 77.922892] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 77.922946] WARNING: CPU: 5 PID: 76 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 77.922947] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 77.922969] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 77.922977] CPU: 5 PID: 76 Comm: kworker/5:1 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 77.922978] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 77.922988] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 77.923016] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 77.923016] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 77.923033] RSP: 0018:ffff9c4f81bb3a10 EFLAGS: 00010297
[ 77.923034] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 77.923035] RDX: 0000000000000000 RSI: ffff8ddf2f556938 RDI: ffff8ddf2f556938
[ 77.923035] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 77.923036] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 77.923037] R13: 0000000000004ba4 R14: 0000000000010000 R15: 0000000000000000
[ 77.923038] FS: 0000000000000000(0000) GS:ffff8ddf2f540000(0000) knlGS:0000000000000000
[ 77.923039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 77.923060] CR2: 00007f4b440d2398 CR3: 000000044820a004 CR4: 00000000003606e0
[ 77.923061] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 77.923061] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 77.923062] Call Trace:
[ 77.923120] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 77.923165] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 77.923224] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 77.923282] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 77.923340] ? hwmgr_handle_task+0x6b/0xc0 [amdgpu]
[ 77.923342] ? _cond_resched+0x15/0x30
[ 77.923383] ? pp_dpm_dispatch_tasks+0x41/0x60 [amdgpu]
[ 77.923410] ? amdgpu_pm_compute_clocks.part.9+0xb7/0x530 [amdgpu]
[ 77.923438] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 77.923466] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 77.923486] ? amdgpu_bo_pin_restricted+0xd6/0x300 [amdgpu]
[ 77.923488] ? _cond_resched+0x15/0x30
[ 77.923489] ? wait_for_completion_timeout+0x3a/0x190
[ 77.923489] ? wait_for_completion_interruptible+0x35/0x1d0
[ 77.923495] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 77.923499] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 77.923506] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 77.923514] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 77.923516] process_one_work+0x1a1/0x350
[ 77.923518] worker_thread+0x30/0x380
[ 77.923519] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 77.923520] kthread+0x112/0x130
[ 77.923522] ? kthread_create_worker_on_cpu+0x70/0x70
[ 77.923523] ret_from_fork+0x35/0x40
[ 77.923542] ---[ end trace db8425ba857d73a9 ]---
[ 80.360279] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 80.360333] WARNING: CPU: 4 PID: 77 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 80.360334] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 80.360358] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 80.360367] CPU: 4 PID: 77 Comm: kworker/4:1 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 80.360368] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 80.360378] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 80.360408] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 80.360409] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 80.360427] RSP: 0018:ffff9c4f81bbba10 EFLAGS: 00010297
[ 80.360428] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 80.360429] RDX: 0000000000000000 RSI: ffff8ddf2f516938 RDI: ffff8ddf2f516938
[ 80.360429] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 80.360430] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 80.360431] R13: 0000000000004ba4 R14: 0000000000010000 R15: 0000000000000000
[ 80.360432] FS: 0000000000000000(0000) GS:ffff8ddf2f500000(0000) knlGS:0000000000000000
[ 80.360432] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 80.360433] CR2: 0000001a66fbfd03 CR3: 000000044820a004 CR4: 00000000003606e0
[ 80.360434] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 80.360434] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 80.360435] Call Trace:
[ 80.360470] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 80.360501] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 80.360531] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 80.360560] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 80.360593] ? dce_pipe_control_lock+0x1da/0x1f0 [amdgpu]
[ 80.360622] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 80.360654] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 80.360676] ? amdgpu_bo_pin_restricted+0xd6/0x300 [amdgpu]
[ 80.360679] ? _cond_resched+0x15/0x30
[ 80.360680] ? wait_for_completion_timeout+0x3a/0x190
[ 80.360681] ? wait_for_completion_interruptible+0x35/0x1d0
[ 80.360687] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 80.360691] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 80.360700] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 80.360708] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 80.360710] process_one_work+0x1a1/0x350
[ 80.360713] worker_thread+0x30/0x380
[ 80.360714] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 80.360716] kthread+0x112/0x130
[ 80.360717] ? kthread_create_worker_on_cpu+0x70/0x70
[ 80.360719] ret_from_fork+0x35/0x40
[ 80.360720] ---[ end trace db8425ba857d73aa ]---
[ 80.436758] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 80.436795] WARNING: CPU: 5 PID: 76 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 80.436795] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 80.436811] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 80.436817] CPU: 5 PID: 76 Comm: kworker/5:1 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 80.436818] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 80.436825] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 80.436850] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 80.436850] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 80.436866] RSP: 0018:ffff9c4f81bb3a10 EFLAGS: 00010297
[ 80.436867] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 80.436868] RDX: 0000000000000000 RSI: ffff8ddf2f556938 RDI: ffff8ddf2f556938
[ 80.436868] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 80.436869] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 80.436869] R13: 0000000000004ea4 R14: 0000000000010000 R15: 0000000000000000
[ 80.436870] FS: 0000000000000000(0000) GS:ffff8ddf2f540000(0000) knlGS:0000000000000000
[ 80.436871] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 80.436871] CR2: 00007f3ffb9f7070 CR3: 000000044820a001 CR4: 00000000003606e0
[ 80.436872] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 80.436872] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 80.436873] Call Trace:
[ 80.436902] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 80.436928] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 80.436953] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 80.436996] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 80.437034] ? hwmgr_handle_task+0x6b/0xc0 [amdgpu]
[ 80.437036] ? _cond_resched+0x15/0x30
[ 80.437063] ? pp_dpm_dispatch_tasks+0x41/0x60 [amdgpu]
[ 80.437083] ? amdgpu_pm_compute_clocks.part.9+0xb7/0x530 [amdgpu]
[ 80.437107] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 80.437135] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 80.437137] ? _cond_resched+0x15/0x30
[ 80.437137] ? wait_for_completion_timeout+0x3a/0x190
[ 80.437138] ? wait_for_completion_interruptible+0x35/0x1d0
[ 80.437139] ? _cond_resched+0x15/0x30
[ 80.437166] ? dm_plane_helper_cleanup_fb+0x120/0x120 [amdgpu]
[ 80.437170] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 80.437173] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 80.437180] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 80.437187] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 80.437189] process_one_work+0x1a1/0x350
[ 80.437190] worker_thread+0x1c9/0x380
[ 80.437192] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 80.437193] kthread+0x112/0x130
[ 80.437194] ? kthread_create_worker_on_cpu+0x70/0x70
[ 80.437195] ret_from_fork+0x35/0x40
[ 80.437196] ---[ end trace db8425ba857d73ab ]---
[ 84.562602] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 84.562653] WARNING: CPU: 6 PID: 155 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 84.562654] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 84.562675] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 84.562683] CPU: 6 PID: 155 Comm: kworker/6:2 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 84.562683] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 84.562693] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 84.562718] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 84.562719] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 84.562734] RSP: 0018:ffff9c4f81ecfa10 EFLAGS: 00010297
[ 84.562735] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 84.562736] RDX: 0000000000000000 RSI: ffff8ddf2f596938 RDI: ffff8ddf2f596938
[ 84.562736] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 84.562737] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 84.562737] R13: 0000000000004ba4 R14: 0000000000010000 R15: 0000000000000000
[ 84.562738] FS: 0000000000000000(0000) GS:ffff8ddf2f580000(0000) knlGS:0000000000000000
[ 84.562739] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 84.562739] CR2: 0000558ee35a9408 CR3: 000000044820a006 CR4: 00000000003606e0
[ 84.562740] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 84.562740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 84.562741] Call Trace:
[ 84.562771] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 84.562797] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 84.562864] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 84.562904] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 84.562942] ? hwmgr_handle_task+0x6b/0xc0 [amdgpu]
[ 84.562945] ? _cond_resched+0x15/0x30
[ 84.562972] ? pp_dpm_dispatch_tasks+0x41/0x60 [amdgpu]
[ 84.562991] ? amdgpu_pm_compute_clocks.part.9+0xb7/0x530 [amdgpu]
[ 84.563016] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 84.563043] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 84.563062] ? amdgpu_bo_pin_restricted+0xd6/0x300 [amdgpu]
[ 84.563063] ? _cond_resched+0x15/0x30
[ 84.563064] ? wait_for_completion_timeout+0x3a/0x190
[ 84.563065] ? wait_for_completion_interruptible+0x35/0x1d0
[ 84.563070] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 84.563074] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 84.563081] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 84.563088] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 84.563090] process_one_work+0x1a1/0x350
[ 84.563092] worker_thread+0x30/0x380
[ 84.563093] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 84.563095] kthread+0x112/0x130
[ 84.563096] ? kthread_create_worker_on_cpu+0x70/0x70
[ 84.563097] ret_from_fork+0x35/0x40
[ 84.563098] ---[ end trace db8425ba857d73ac ]---
[ 84.633249] [drm:generic_reg_wait [amdgpu]] ERROR REG_WAIT timeout 10us * 3000 tries - dce110_stream_encoder_dp_blank line:927
[ 84.633296] WARNING: CPU: 6 PID: 155 at drivers/gpu/drm/amd/amdgpu/../display/dc/dc_helper.c:254 generic_reg_wait+0xe7/0x160 [amdgpu]
[ 84.633296] Modules linked in: fuse vfat fat arc4 rtsx_pci_sdmmc mmc_core mei_wdt rtsx_pci_ms intel_rapl memstick iTCO_wdt iTCO_vendor_support hp_wmi intel_wmi_thunderbolt wmi_bmof sparse_keymap x86_pkg_temp_thermal intel_powerclamp coretemp iwlmvm kvm mac80211 snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul snd_hda_intel snd_usb_audio snd_hda_codec ghash_clmulni_intel intel_cstate btusb snd_hda_core btrtl snd_usbmidi_lib iwlwifi intel_uncore snd_rawmidi snd_hwdep snd_seq btbcm intel_rapl_perf btintel snd_seq_device snd_pcm uvcvideo bluetooth cfg80211 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev thunderbolt snd_timer snd media mei_me ecdh_generic i2c_i801 rtsx_pci rfkill mei soundcore intel_pch_thermal wmi
[ 84.633317] acpi_pad hp_accel lis3lv02d input_polldev hp_wireless pcc_cpufreq amdgpu i915 chash gpu_sched i2c_algo_bit drm_kms_helper tg3 ttm drm serio_raw libphy e1000e crc32c_intel video
[ 84.633325] CPU: 6 PID: 155 Comm: kworker/6:2 Tainted: G W 4.18.8-200.fc28.x86_64 #1 (closed)
[ 84.633326] Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.22 05/17/2018
[ 84.633335] Workqueue: events drm_mode_rmfb_work_fn [drm]
[ 84.633360] RIP: 0010:generic_reg_wait+0xe7/0x160 [amdgpu]
[ 84.633360] Code: 44 24 58 8b 54 24 48 89 de 44 89 4c 24 08 48 8b 4c 24 50 48 c7 c7 80 72 a3 c0 e8 64 5f b5 ff 83 7d 20 01 44 8b 4c 24 08 74 02 <0f> 0b 48 83 c4 10 44 89 c8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 0f
[ 84.633376] RSP: 0018:ffff9c4f81ecfa10 EFLAGS: 00010297
[ 84.633377] RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000000
[ 84.633378] RDX: 0000000000000000 RSI: ffff8ddf2f596938 RDI: ffff8ddf2f596938
[ 84.633378] RBP: ffff8ddf14c09b80 R08: 0000000000000005 R09: 0000000000010200
[ 84.633379] R10: 0000000000000000 R11: ffffffff969a11ed R12: 0000000000000bb9
[ 84.633379] R13: 0000000000004ea4 R14: 0000000000010000 R15: 0000000000000000
[ 84.633380] FS: 0000000000000000(0000) GS:ffff8ddf2f580000(0000) knlGS:0000000000000000
[ 84.633381] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 84.633381] CR2: 0000558ee35a9408 CR3: 000000044820a006 CR4: 00000000003606e0
[ 84.633382] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 84.633382] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 84.633383] Call Trace:
[ 84.633413] dce110_stream_encoder_dp_blank+0x12c/0x1a0 [amdgpu]
[ 84.633439] core_link_disable_stream+0x54/0x220 [amdgpu]
[ 84.633464] dce110_reset_hw_ctx_wrap+0xc1/0x1e0 [amdgpu]
[ 84.633490] dce110_apply_ctx_to_hw+0x52/0xa30 [amdgpu]
[ 84.633515] ? hwmgr_handle_task+0x6b/0xc0 [amdgpu]
[ 84.633518] ? _cond_resched+0x15/0x30
[ 84.633544] ? pp_dpm_dispatch_tasks+0x41/0x60 [amdgpu]
[ 84.633564] ? amdgpu_pm_compute_clocks.part.9+0xb7/0x530 [amdgpu]
[ 84.633589] dc_commit_state+0x2e7/0x580 [amdgpu]
[ 84.633616] amdgpu_dm_atomic_commit_tail+0x37c/0xd70 [amdgpu]
[ 84.633635] ? amdgpu_bo_pin_restricted+0xd6/0x300 [amdgpu]
[ 84.633636] ? _cond_resched+0x15/0x30
[ 84.633637] ? wait_for_completion_timeout+0x3a/0x190
[ 84.633638] ? wait_for_completion_interruptible+0x35/0x1d0
[ 84.633643] commit_tail+0x3d/0x70 [drm_kms_helper]
[ 84.633647] drm_atomic_helper_commit+0x103/0x110 [drm_kms_helper]
[ 84.633654] drm_framebuffer_remove+0x2cc/0x3e0 [drm]
[ 84.633661] drm_mode_rmfb_work_fn+0x4f/0x60 [drm]
[ 84.633663] process_one_work+0x1a1/0x350
[ 84.633665] worker_thread+0x30/0x380
[ 84.633666] ? pwq_unbound_release_workfn+0xd0/0xd0
[ 84.633668] kthread+0x112/0x130
[ 84.633669] ? kthread_create_worker_on_cpu+0x70/0x70
[ 84.633670] ret_from_fork+0x35/0x40
[ 84.633671] ---[ end trace db8425ba857d73ad ]---

I've observed this with both 4.18.8 and the latest upstream kernel.