Just adding output from my machine: $ uname -a Linux faxnet 4.16.4-1-ARCH #1 SMP PREEMPT Tue Apr 24 13:21:29 UTC 2018 x86_64 GNU/Linux $ lspci | grep -i vga 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 03) $ dmesg | awk '/\[ cut here \]/{flag=1}/\[ end trace .* \]/{print;flag=0}flag' [ 18.930181] ------------[ cut here ]------------ [ 18.930188] vblank wait timed out on crtc 0 [ 18.930302] WARNING: CPU: 0 PID: 148 at drivers/gpu/drm/drm_vblank.c:1073 drm_wait_one_vblank+0x169/0x170 [drm] [ 18.930305] Modules linked in: 8021q mrp snd_hda_codec_realtek snd_hda_codec_generic nls_iso8859_1 snd_hda_intel nls_cp437 coretemp vfat snd_hda_codec fat joydev kvm_intel iTCO_wdt kvm iTCO_vendor_support snd_hda_core b43 applesmc irqbypass bcma input_polldev isight_firmware mac80211 appletouch input_leds snd_hwdep hid_apple mousedev i915 snd_pcm pcspkr cfg80211 i2c_i801 i2c_algo_bit rfkill snd_timer led_class rng_core drm_kms_helper sky2 drm sbs lpc_ich snd sbshc ac intel_agp intel_gtt evdev syscopyarea rtc_cmos soundcore agpgart mac_hid apple_bl sysfillrect shpchp sysimgblt fb_sys_fops acpi_cpufreq ip_tables x_tables crc32c_generic ext4 crc16 mbcache jbd2 fscrypto hid_appleir hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi ssb_hcd ahci ata_piix libahci uhci_hcd libata firewire_ohci [ 18.930457] scsi_mod firewire_core crc_itu_t ssb pcmcia ehci_pci pcmcia_core ehci_hcd mmc_core usbcore usb_common [ 18.930484] CPU: 0 PID: 148 Comm: kworker/u4:2 Not tainted 4.16.4-1-ARCH #1 [ 18.930488] Hardware name: Apple Inc. MacBook4,1/Mac-F22788A9, BIOS MB41.88Z.00C1.B00.0802091535 02/09/08 [ 18.930500] Workqueue: events_unbound async_run_entry_fn [ 18.930540] RIP: 0010:drm_wait_one_vblank+0x169/0x170 [drm] [ 18.930544] RSP: 0018:ffff9ee98060bab0 EFLAGS: 00010286 [ 18.930549] RAX: 0000000000000000 RBX: ffff9bf5b8c88000 RCX: 0000000000000001 [ 18.930553] RDX: 0000000080000001 RSI: ffffffff8ee6807c RDI: 00000000ffffffff [ 18.930557] RBP: 0000000000000000 R08: 0000000000000030 R09: 00000000000003e0 [ 18.930560] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 18.930564] R13: 0000000001000001 R14: ffff9bf57791b808 R15: ffff9bf5b862b400 [ 18.930569] FS: 0000000000000000(0000) GS:ffff9bf5bce00000(0000) knlGS:0000000000000000 [ 18.930574] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 18.930577] CR2: 00005572f7a48518 CR3: 000000004800a000 CR4: 00000000000006f0 [ 18.930580] Call Trace: [ 18.930597] ? wait_woken+0x80/0x80 [ 18.930754] intel_get_load_detect_pipe+0x363/0x3d0 [i915] [ 18.930889] intel_tv_detect+0x147/0x500 [i915] [ 18.930927] ? drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 18.930946] drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 18.930973] drm_setup_crtcs+0x13d/0xaf0 [drm_kms_helper] [ 18.930983] ? dequeue_entity+0x38d/0x970 [ 18.931005] __drm_fb_helper_initial_config_and_unlock+0x39/0x430 [drm_kms_helper] [ 18.931012] ? finish_task_switch+0x85/0x2c0 [ 18.931144] intel_fbdev_initial_config+0x14/0x30 [i915] [ 18.931154] async_run_entry_fn+0x37/0x140 [ 18.931163] process_one_work+0x1ce/0x3f0 [ 18.931170] worker_thread+0x2b/0x3d0 [ 18.931177] ? process_one_work+0x3f0/0x3f0 [ 18.931182] kthread+0x113/0x130 [ 18.931188] ? kthread_create_on_node+0x70/0x70 [ 18.931197] ret_from_fork+0x35/0x40 [ 18.931204] Code: 2d ff ff ff e8 49 7d ac cd 48 89 e6 4c 89 f7 e8 ce e6 b0 cd 45 85 e4 0f 85 0a ff ff ff 89 ee 48 c7 c7 68 48 5d c0 e8 97 7a ac cd <0f> 0b e9 f5 fe ff ff 66 66 66 66 90 8b b7 90 00 00 00 48 8b 3f [ 18.931316] ---[ end trace 8a889bc87cc30d7f ]--- [ 50.076888] ------------[ cut here ]------------ [ 50.076895] vblank wait timed out on crtc 1 [ 50.077014] WARNING: CPU: 1 PID: 270 at drivers/gpu/drm/drm_vblank.c:1073 drm_wait_one_vblank+0x169/0x170 [drm] [ 50.077017] Modules linked in: 8021q mrp snd_hda_codec_realtek snd_hda_codec_generic nls_iso8859_1 snd_hda_intel nls_cp437 coretemp vfat snd_hda_codec fat joydev kvm_intel iTCO_wdt kvm iTCO_vendor_support snd_hda_core b43 applesmc irqbypass bcma input_polldev isight_firmware mac80211 appletouch input_leds snd_hwdep hid_apple mousedev i915 snd_pcm pcspkr cfg80211 i2c_i801 i2c_algo_bit rfkill snd_timer led_class rng_core drm_kms_helper sky2 drm sbs lpc_ich snd sbshc ac intel_agp intel_gtt evdev syscopyarea rtc_cmos soundcore agpgart mac_hid apple_bl sysfillrect shpchp sysimgblt fb_sys_fops acpi_cpufreq ip_tables x_tables crc32c_generic ext4 crc16 mbcache jbd2 fscrypto hid_appleir hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi ssb_hcd ahci ata_piix libahci uhci_hcd libata firewire_ohci [ 50.077179] scsi_mod firewire_core crc_itu_t ssb pcmcia ehci_pci pcmcia_core ehci_hcd mmc_core usbcore usb_common [ 50.077206] CPU: 1 PID: 270 Comm: kworker/1:3 Tainted: G W 4.16.4-1-ARCH #1 [ 50.077210] Hardware name: Apple Inc. MacBook4,1/Mac-F22788A9, BIOS MB41.88Z.00C1.B00.0802091535 02/09/08 [ 50.077237] Workqueue: events output_poll_execute [drm_kms_helper] [ 50.077283] RIP: 0010:drm_wait_one_vblank+0x169/0x170 [drm] [ 50.077287] RSP: 0018:ffff9ee9807cfac0 EFLAGS: 00010282 [ 50.077292] RAX: 0000000000000000 RBX: ffff9bf5b8c88000 RCX: 0000000000000001 [ 50.077296] RDX: 0000000080000001 RSI: ffffffff8ee6807c RDI: 00000000ffffffff [ 50.077300] RBP: 0000000000000001 R08: 0000000000000030 R09: 000000000000040c [ 50.077303] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 50.077307] R13: 0000000001000012 R14: ffff9bf57791b968 R15: ffff9bf5b3e76400 [ 50.077312] FS: 0000000000000000(0000) GS:ffff9bf5bcf00000(0000) knlGS:0000000000000000 [ 50.077316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 50.077320] CR2: 00007efd6942bef0 CR3: 000000004800a000 CR4: 00000000000006e0 [ 50.077323] Call Trace: [ 50.077343] ? wait_woken+0x80/0x80 [ 50.077459] intel_get_load_detect_pipe+0x363/0x3d0 [i915] [ 50.077554] intel_tv_detect+0x147/0x500 [i915] [ 50.077585] ? drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 50.077605] drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 50.077632] drm_setup_crtcs+0x13d/0xaf0 [drm_kms_helper] [ 50.077656] ? drm_fb_helper_is_bound.isra.16+0x76/0xa0 [drm_kms_helper] [ 50.077678] drm_fb_helper_hotplug_event.part.28+0x8b/0xb0 [drm_kms_helper] [ 50.077697] output_poll_execute+0xa2/0x1b0 [drm_kms_helper] [ 50.077712] process_one_work+0x1ce/0x3f0 [ 50.077720] worker_thread+0x2b/0x3d0 [ 50.077727] ? process_one_work+0x3f0/0x3f0 [ 50.077733] kthread+0x113/0x130 [ 50.077739] ? kthread_create_on_node+0x70/0x70 [ 50.077746] ? do_syscall_64+0x74/0x190 [ 50.077753] ? SyS_exit_group+0x10/0x10 [ 50.077761] ret_from_fork+0x35/0x40 [ 50.077768] Code: 2d ff ff ff e8 49 7d ac cd 48 89 e6 4c 89 f7 e8 ce e6 b0 cd 45 85 e4 0f 85 0a ff ff ff 89 ee 48 c7 c7 68 48 5d c0 e8 97 7a ac cd <0f> 0b e9 f5 fe ff ff 66 66 66 66 90 8b b7 90 00 00 00 48 8b 3f [ 50.077880] ---[ end trace 8a889bc87cc30d80 ]--- [ 80.583270] ------------[ cut here ]------------ [ 80.583273] vblank wait timed out on crtc 1 [ 80.583351] WARNING: CPU: 1 PID: 270 at drivers/gpu/drm/drm_vblank.c:1073 drm_wait_one_vblank+0x169/0x170 [drm] [ 80.583353] Modules linked in: 8021q mrp snd_hda_codec_realtek snd_hda_codec_generic nls_iso8859_1 snd_hda_intel nls_cp437 coretemp vfat snd_hda_codec fat joydev kvm_intel iTCO_wdt kvm iTCO_vendor_support snd_hda_core b43 applesmc irqbypass bcma input_polldev isight_firmware mac80211 appletouch input_leds snd_hwdep hid_apple mousedev i915 snd_pcm pcspkr cfg80211 i2c_i801 i2c_algo_bit rfkill snd_timer led_class rng_core drm_kms_helper sky2 drm sbs lpc_ich snd sbshc ac intel_agp intel_gtt evdev syscopyarea rtc_cmos soundcore agpgart mac_hid apple_bl sysfillrect shpchp sysimgblt fb_sys_fops acpi_cpufreq ip_tables x_tables crc32c_generic ext4 crc16 mbcache jbd2 fscrypto hid_appleir hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi ssb_hcd ahci ata_piix libahci uhci_hcd libata firewire_ohci [ 80.583460] scsi_mod firewire_core crc_itu_t ssb pcmcia ehci_pci pcmcia_core ehci_hcd mmc_core usbcore usb_common [ 80.583478] CPU: 1 PID: 270 Comm: kworker/1:3 Tainted: G W 4.16.4-1-ARCH #1 [ 80.583480] Hardware name: Apple Inc. MacBook4,1/Mac-F22788A9, BIOS MB41.88Z.00C1.B00.0802091535 02/09/08 [ 80.583494] Workqueue: events output_poll_execute [drm_kms_helper] [ 80.583521] RIP: 0010:drm_wait_one_vblank+0x169/0x170 [drm] [ 80.583523] RSP: 0018:ffff9ee9807cfac0 EFLAGS: 00010282 [ 80.583527] RAX: 0000000000000000 RBX: ffff9bf5b8c88000 RCX: 0000000000000001 [ 80.583530] RDX: 0000000080000001 RSI: ffffffff8ee6807c RDI: 00000000ffffffff [ 80.583532] RBP: 0000000000000001 R08: 0000000000000030 R09: 0000000000000435 [ 80.583534] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 80.583537] R13: 0000000003000013 R14: ffff9bf57791b968 R15: ffff9bf5b3e76400 [ 80.583540] FS: 0000000000000000(0000) GS:ffff9bf5bcf00000(0000) knlGS:0000000000000000 [ 80.583543] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 80.583546] CR2: 000055817b4b9e78 CR3: 000000004800a000 CR4: 00000000000006e0 [ 80.583548] Call Trace: [ 80.583560] ? wait_woken+0x80/0x80 [ 80.583634] intel_get_load_detect_pipe+0x363/0x3d0 [i915] [ 80.583697] intel_tv_detect+0x147/0x500 [i915] [ 80.583717] ? drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 80.583729] drm_helper_probe_single_connector_modes+0xd8/0x6e0 [drm_kms_helper] [ 80.583747] drm_setup_crtcs+0x13d/0xaf0 [drm_kms_helper] [ 80.583764] ? drm_fb_helper_is_bound.isra.16+0x76/0xa0 [drm_kms_helper] [ 80.583778] drm_fb_helper_hotplug_event.part.28+0x8b/0xb0 [drm_kms_helper] [ 80.583791] output_poll_execute+0x185/0x1b0 [drm_kms_helper] [ 80.583798] process_one_work+0x1ce/0x3f0 [ 80.583803] worker_thread+0x241/0x3d0 [ 80.583808] ? process_one_work+0x3f0/0x3f0 [ 80.583812] kthread+0x113/0x130 [ 80.583816] ? kthread_create_on_node+0x70/0x70 [ 80.583821] ? do_syscall_64+0x74/0x190 [ 80.583825] ? SyS_exit_group+0x10/0x10 [ 80.583831] ret_from_fork+0x35/0x40 [ 80.583835] Code: 2d ff ff ff e8 49 7d ac cd 48 89 e6 4c 89 f7 e8 ce e6 b0 cd 45 85 e4 0f 85 0a ff ff ff 89 ee 48 c7 c7 68 48 5d c0 e8 97 7a ac cd <0f> 0b e9 f5 fe ff ff 66 66 66 66 90 8b b7 90 00 00 00 48 8b 3f [ 80.583910] ---[ end trace 8a889bc87cc30d81 ]---