Sometimes, my laptop does not freeze.  Just now I was able to see the external display upon my second attempt, and found 8 backtraces in dmesg:

[26529.773617] [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* failed
 to enable link training
[26529.776319] [drm:intel_dp_link_training_channel_equalization [i915]] *ERROR* 
failed to start channel equalization
[26529.778857] [drm:intel_mst_pre_enable_dp [i915]] *ERROR* failed to allocate v
cpi
[26529.845810] ------------[ cut here ]------------
[26529.845837] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:12740 intel_modeset_check_state+0x5b3/0x8a0 [i915]()
[26529.845838] encoder detached but still enabled on pipe A.
[26529.845839] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26529.845870]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26529.845882] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26529.845884] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26529.845885]  0000000000000286 0000000088216a49 ffff880034c97b08 ffffffff813e9c53
[26529.845887]  ffff880034c97b50 ffffffffc027ca50 ffff880034c97b40 ffffffff81080fb2
[26529.845889]  ffff8802443c4318 ffff8800356b1000 ffff8802443c4348 ffff8802443c4330
[26529.845890] Call Trace:
[26529.845895]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26529.845898]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26529.845899]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26529.845916]  [<ffffffffc020d483>] intel_modeset_check_state+0x5b3/0x8a0 [i915]
[26529.845932]  [<ffffffffc0218bcb>] intel_atomic_commit+0x4bb/0x6f0 [i915]
[26529.845947]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26529.845954]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26529.845964]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26529.845974]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26529.845981]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26529.845984]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26529.845992]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26529.845995]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26529.845997]  [<ffffffff8103b32d>] ? fpu__restore_sig+0x4d/0x60
[26529.845999]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26529.846002]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26529.846004] ---[ end trace 1dc2836a34f42c84 ]---



[26530.067034] ------------[ cut here ]------------
[26530.067056] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:12732 intel_modeset_check_state+0x563/0x8a0 [i915]()
[26530.067057] encoder's enabled state mismatch (expected 1, found 0)
[26530.067057] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.067085]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.067096] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.067097] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.067098]  0000000000000286 0000000088216a49 ffff880034c97b08 ffffffff813e9c53
[26530.067100]  ffff880034c97b50 ffffffffc027ca50 ffff880034c97b40 ffffffff81080fb2
[26530.067101]  ffff8802443c4318 ffff880035505b00 ffff8802443c4348 ffff8802443c4330
[26530.067103] Call Trace:
[26530.067107]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.067109]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.067111]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.067125]  [<ffffffffc020d433>] intel_modeset_check_state+0x563/0x8a0 [i915]
[26530.067138]  [<ffffffffc022027e>] ? intel_cleanup_plane_fb+0x4e/0x70 [i915]
[26530.067150]  [<ffffffffc0218bcb>] intel_atomic_commit+0x4bb/0x6f0 [i915]
[26530.067162]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.067168]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.067177]  [<ffffffffc005b46a>] ? drm_modeset_lock_all_ctx+0x9a/0xb0 [drm]
[26530.067185]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.067193]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.067199]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.067205]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.067208]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.067210]  [<ffffffff8120eee1>] ? __sb_end_write+0x21/0x30
[26530.067211]  [<ffffffff8120caed>] ? vfs_write+0x15d/0x1a0
[26530.067213]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.067215]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.067217] ---[ end trace 1dc2836a34f42c85 ]---




[26530.307982] [drm:intel_mst_pre_enable_dp [i915]] *ERROR* can't find connector
[26530.307986] ------------[ cut here ]------------
[26530.308001] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_ddi.c:744 intel_ddi_get_crtc_encoder+0x87/0x90 [i915]()
[26530.308002] 2 encoders on crtc for pipe A
[26530.308003] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.308031]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.308043] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.308044] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.308045]  0000000000000286 0000000088216a49 ffff880034c97aa8 ffffffff813e9c53
[26530.308046]  ffff880034c97af0 ffffffffc0282bf8 ffff880034c97ae0 ffffffff81080fb2
[26530.308048]  ffff880035505b00 ffff880035690000 ffff880035690000 ffff8802443c4340
[26530.308050] Call Trace:
[26530.308053]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.308056]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.308057]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.308072]  [<ffffffffc0234797>] intel_ddi_get_crtc_encoder+0x87/0x90 [i915]
[26530.308085]  [<ffffffffc0237a6e>] intel_ddi_enable_pipe_clock+0x2e/0x90 [i915]
[26530.308099]  [<ffffffffc021bfcc>] haswell_crtc_enable+0x71c/0x870 [i915]
[26530.308113]  [<ffffffffc0218b64>] intel_atomic_commit+0x454/0x6f0 [i915]
[26530.308125]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.308131]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.308139]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.308148]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.308154]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.308162]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.308164]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.308166]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.308168]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.308170]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.308171]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.308174]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.308175] ---[ end trace 1dc2836a34f42c86 ]---



[26530.308287] ------------[ cut here ]------------
[26530.308302] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_ddi.c:744 intel_ddi_get_crtc_encoder+0x87/0x90 [i915]()
[26530.308303] 2 encoders on crtc for pipe A
[26530.308303] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.308323]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.308332] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.308332] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.308333]  0000000000000286 0000000088216a49 ffff880034c97ac0 ffffffff813e9c53
[26530.308335]  ffff880034c97b08 ffffffffc0282bf8 ffff880034c97af8 ffffffff81080fb2
[26530.308336]  ffff880035505b00 ffff880035690000 ffff880035690000 ffff8802443c4340
[26530.308338] Call Trace:
[26530.308340]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.308341]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.308343]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.308357]  [<ffffffffc0234797>] intel_ddi_get_crtc_encoder+0x87/0x90 [i915]
[26530.308371]  [<ffffffffc023755b>] intel_ddi_set_pipe_settings+0x1b/0xa0 [i915]
[26530.308385]  [<ffffffffc021bc0e>] haswell_crtc_enable+0x35e/0x870 [i915]
[26530.308399]  [<ffffffffc0218b64>] intel_atomic_commit+0x454/0x6f0 [i915]
[26530.308409]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.308413]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.308421]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.308430]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.308436]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.308444]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.308446]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.308447]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.308449]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.308450]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.308452]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.308454]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.308455] ---[ end trace 1dc2836a34f42c87 ]---


[26530.308457] ------------[ cut here ]------------
[26530.308471] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/driv
ers/gpu/drm/i915/intel_ddi.c:744 intel_ddi_get_crtc_encoder+0x87/0x90 [i915]()
[26530.308472] 2 encoders on crtc for pipe A
[26530.308472] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vbox
netflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.308492]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.308501] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.308501] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.308502]  0000000000000286 0000000088216a49 ffff880034c97a80 ffffffff813e9c53
[26530.308504]  ffff880034c97ac8 ffffffffc0282bf8 ffff880034c97ab8 ffffffff81080fb2
[26530.308505]  ffff880035505b00 ffff88023f226000 ffff880035690000 ffff8802443c4340
[26530.308507] Call Trace:
[26530.308509]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.308511]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.308512]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.308514]  [<ffffffff8108104c>] ? warn_slowpath_fmt+0x5c/0x80
[26530.308528]  [<ffffffffc0234797>] intel_ddi_get_crtc_encoder+0x87/0x90 [i915]
[26530.308541]  [<ffffffffc023768d>] intel_ddi_enable_transcoder_func+0x2d/0x260 [i915]
[26530.308555]  [<ffffffffc021bfbf>] haswell_crtc_enable+0x70f/0x870 [i915]
[26530.308569]  [<ffffffffc0218b64>] intel_atomic_commit+0x454/0x6f0 [i915]
[26530.308579]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.308584]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.308592]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.308600]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.308606]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.308614]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.308616]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.308618]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.308620]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.308621]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.308622]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.308624]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.308626] ---[ end trace 1dc2836a34f42c88 ]---


[26530.375450] ------------[ cut here ]------------
[26530.375477] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:12732 intel_modeset_check_state+0x563/0x8a0 [i915]()
[26530.375479] encoder's enabled state mismatch (expected 1, found 0)
[26530.375480] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.375511]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.375523] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.375525] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.375526]  0000000000000286 0000000088216a49 ffff880034c97b08 ffffffff813e9c53
[26530.375528]  ffff880034c97b50 ffffffffc027ca50 ffff880034c97b40 ffffffff81080fb2
[26530.375530]  ffff8802443c4318 ffff880035505b00 ffff8802443c4348 ffff8802443c4330
[26530.375531] Call Trace:
[26530.375536]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.375539]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.375540]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.375557]  [<ffffffffc020d433>] intel_modeset_check_state+0x563/0x8a0 [i915]
[26530.375573]  [<ffffffffc0218bcb>] intel_atomic_commit+0x4bb/0x6f0 [i915]
[26530.375588]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.375595]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.375605]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.375615]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.375622]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.375631]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.375634]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.375636]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.375638]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.375640]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.375641]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.375645]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.375646] ---[ end trace 1dc2836a34f42c89 ]---

[26530.375659] ------------[ cut here ]------------
[26530.375678] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:12794 intel_modeset_check_state+0x714/0x8a0 [i915]()
[26530.375679] [ENCODER:41] active 0 with crtc active 1
[26530.375680] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.375704]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.375713] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.375714] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.375715]  0000000000000286 0000000088216a49 ffff880034c97b08 ffffffff813e9c53
[26530.375717]  ffff880034c97b50 ffffffffc027ca50 ffff880034c97b40 ffffffff81080fb2
[26530.375719]  ffff880035505b00 ffff88023f226000 ffff8801b2d3d200 ffff88024161c400
[26530.375721] Call Trace:
[26530.375723]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.375725]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.375727]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.375746]  [<ffffffffc02360b7>] ? intel_ddi_get_config+0xe7/0x210 [i915]
[26530.375763]  [<ffffffffc020d5e4>] intel_modeset_check_state+0x714/0x8a0 [i915]
[26530.375781]  [<ffffffffc0218bcb>] intel_atomic_commit+0x4bb/0x6f0 [i915]
[26530.375794]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.375799]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.375809]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.375820]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.375828]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.375838]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.375840]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.375842]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.375844]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.375846]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.375848]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.375850]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.375852] ---[ end trace 1dc2836a34f42c8a ]---



[26530.375872] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in ddi_pll_sel (expected 0x20000000, found 0x00000000)
[26530.375890] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in base.adjusted_mode.crtc_clock (expected 140000, found 279999)
[26530.375908] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in port_clock (expected 270000, found 540000)
[26530.375909] ------------[ cut here ]------------
[26530.375927] WARNING: CPU: 3 PID: 1780 at /build/linux-FvcHlK/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:12810 intel_modeset_check_state+0x6a0/0x8a0 [i915]()
[26530.375927] pipe state doesn't match!
[26530.375928] Modules linked in: cpuid pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media btusb btrtl btbcm btintel bluetooth intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel arc4 kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul aesni_intel iwlmvm aes_x86_64 lrw gf128mul mac80211 glue_helper snd_seq_midi snd_seq_midi_event ablk_helper snd_rawmidi cryptd input_leds joydev snd_hda_codec_realtek iwlwifi serio_raw snd_hda_codec_generic thinkpad_acpi nvram cfg80211 snd_hda_intel intel_pch_thermal snd_hda_codec mei_me snd_hda_core mei lpc_ich snd_hwdep snd_pcm shpchp snd_seq snd_seq_device snd_timer snd soundcore
[26530.375952]  mac_hid parport_pc ppdev lp parport autofs4 ses enclosure uas usb_storage i915 i2c_algo_bit drm_kms_helper psmouse syscopyarea sysfillrect e1000e sysimgblt ahci fb_sys_fops libahci drm ptp pps_core wmi video fjes
[26530.375961] CPU: 3 PID: 1780 Comm: Xorg Tainted: G        W  OE   4.4.0-22-generic #40-Ubuntu
[26530.375962] Hardware name: LENOVO 20BS0031US/20BS0031US, BIOS N14ET29W (1.07 ) 05/08/2015
[26530.375963]  0000000000000286 0000000088216a49 ffff880034c97b08 ffffffff813e9c53
[26530.375965]  ffff880034c97b50 ffffffffc027ca50 ffff880034c97b40 ffffffff81080fb2
[26530.375967]  ffff880241619000 ffff88023f226000 ffff8801b2d3d200 ffff88024161c400
[26530.375969] Call Trace:
[26530.375971]  [<ffffffff813e9c53>] dump_stack+0x63/0x90
[26530.375973]  [<ffffffff81080fb2>] warn_slowpath_common+0x82/0xc0
[26530.375975]  [<ffffffff8108104c>] warn_slowpath_fmt+0x5c/0x80
[26530.375993]  [<ffffffffc020d570>] intel_modeset_check_state+0x6a0/0x8a0 [i915]
[26530.376011]  [<ffffffffc0218bcb>] intel_atomic_commit+0x4bb/0x6f0 [i915]
[26530.376024]  [<ffffffffc005cc47>] drm_atomic_commit+0x37/0x60 [drm]
[26530.376029]  [<ffffffffc01719f6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
[26530.376039]  [<ffffffffc004be02>] drm_mode_set_config_internal+0x62/0x100 [drm]
[26530.376050]  [<ffffffffc0050322>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
[26530.376057]  [<ffffffffc0041712>] drm_ioctl+0x152/0x540 [drm]
[26530.376068]  [<ffffffffc004ff50>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[26530.376070]  [<ffffffff8122026f>] do_vfs_ioctl+0x29f/0x490
[26530.376072]  [<ffffffff8108e0e1>] ? __set_task_blocked+0x41/0xa0
[26530.376074]  [<ffffffff81090a76>] ? __set_current_blocked+0x36/0x60
[26530.376075]  [<ffffffff812204d9>] SyS_ioctl+0x79/0x90
[26530.376077]  [<ffffffff81090d2e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[26530.376080]  [<ffffffff818252f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[26530.376081] ---[ end trace 1dc2836a34f42c8b ]---