I just had the same on Lenovo T430 / 14.04.2 Linux ubutp 3.16.0-33-generic #44~14.04.1-Ubuntu SMP Fri Mar 13 10:33:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux Apr 5 09:40:47 ubutp kernel: [ 5286.229834] ------------[ cut here ]------------ Apr 5 09:40:47 ubutp kernel: [ 5286.229893] WARNING: CPU: 2 PID: 19666 at /build/buildd/linux-lts-utopic-3.16.0/drivers/gpu/drm/i915/intel_display.c:3324 intel_crtc_wait_for_pending_flips+0x171/0x180 [i915]() Apr 5 09:40:47 ubutp kernel: [ 5286.229896] Modules linked in: vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) pci_stub nls_iso8859_1 ctr ccm btusb snd_hda_codec_hdmi snd_hda_codec_realtek rfcomm snd_hda_codec_generic bnep bluetooth snd_hda_intel 6lowpan_iphc snd_hda_controller snd_hda_codec snd_hwdep snd_pcm intel_rapl x86_pkg_temp_thermal snd_seq_midi uvcvideo snd_seq_midi_event intel_powerclamp coretemp videobuf2_vmalloc snd_rawmidi videobuf2_memops arc4 snd_seq videobuf2_core kvm_intel v4l2_common kvm iwldvm thinkpad_acpi mac80211 videodev media serio_raw snd_seq_device snd_timer nvram snd iwlwifi rtsx_pci_ms cfg80211 memstick lpc_ich soundcore shpchp mei_me parport_pc mei ppdev mac_hid lp parport dm_crypt uas usb_storage rtsx_pci_sdmmc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw i915 gf128mul glue_helper ablk_helper cryptd psmouse i2c_algo_bit drm_kms_helper ahci e1000e drm libahci ptp rtsx_pci pps_core wmi video [last unloaded: vboxdrv] Apr 5 09:40:47 ubutp kernel: [ 5286.229966] CPU: 2 PID: 19666 Comm: Xorg Tainted: G OE 3.16.0-33-generic #44~14.04.1-Ubuntu Apr 5 09:40:47 ubutp kernel: [ 5286.229969] Hardware name: LENOVO 23501F9/23501F9, BIOS G1ET98WW (2.58 ) 10/23/2013 Apr 5 09:40:47 ubutp kernel: [ 5286.229971] 0000000000000009 ffff8800c796fbf0 ffffffff81763720 0000000000000000 Apr 5 09:40:47 ubutp kernel: [ 5286.229976] ffff8800c796fc28 ffffffff8106dd7d 0000000000000000 ffff880215c19000 Apr 5 09:40:47 ubutp kernel: [ 5286.229979] ffff880035fb8210 ffff8800c720f800 ffff8800c720f800 ffff8800c796fc38 Apr 5 09:40:47 ubutp kernel: [ 5286.229983] Call Trace: Apr 5 09:40:47 ubutp kernel: [ 5286.229993] [] dump_stack+0x45/0x56 Apr 5 09:40:47 ubutp kernel: [ 5286.230001] [] warn_slowpath_common+0x7d/0xa0 Apr 5 09:40:47 ubutp kernel: [ 5286.230006] [] warn_slowpath_null+0x1a/0x20 Apr 5 09:40:47 ubutp kernel: [ 5286.230037] [] intel_crtc_wait_for_pending_flips+0x171/0x180 [i915] Apr 5 09:40:47 ubutp kernel: [ 5286.230045] [] ? prepare_to_wait_event+0x100/0x100 Apr 5 09:40:47 ubutp kernel: [ 5286.230073] [] intel_crtc_disable_planes+0x33/0x1c0 [i915] Apr 5 09:40:47 ubutp kernel: [ 5286.230100] [] ironlake_crtc_disable+0x4d/0x920 [i915] Apr 5 09:40:47 ubutp kernel: [ 5286.230130] [] ? drm_modeset_lock+0x33/0xe0 [drm] Apr 5 09:40:47 ubutp kernel: [ 5286.230136] [] ? mutex_lock+0x12/0x2f Apr 5 09:40:47 ubutp kernel: [ 5286.230165] [] intel_crtc_update_dpms+0x67/0xa0 [i915] Apr 5 09:40:47 ubutp kernel: [ 5286.230194] [] intel_connector_dpms+0x59/0x70 [i915] Apr 5 09:40:47 ubutp kernel: [ 5286.230219] [] drm_mode_obj_set_property_ioctl+0x39f/0x3b0 [drm] Apr 5 09:40:47 ubutp kernel: [ 5286.230242] [] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm] Apr 5 09:40:47 ubutp kernel: [ 5286.230258] [] drm_ioctl+0x1ec/0x660 [drm] Apr 5 09:40:47 ubutp kernel: [ 5286.230268] [] ? backlight_generate_event+0x5c/0x80 Apr 5 09:40:47 ubutp kernel: [ 5286.230274] [] ? fsnotify+0x228/0x2f0 Apr 5 09:40:47 ubutp kernel: [ 5286.230279] [] do_vfs_ioctl+0x2e0/0x4c0 Apr 5 09:40:47 ubutp kernel: [ 5286.230283] [] ? __sb_end_write+0x31/0x60 Apr 5 09:40:47 ubutp kernel: [ 5286.230288] [] ? vfs_write+0x172/0x1f0 Apr 5 09:40:47 ubutp kernel: [ 5286.230292] [] SyS_ioctl+0x81/0xa0 Apr 5 09:40:47 ubutp kernel: [ 5286.230296] [] ? SyS_poll+0x65/0x100 Apr 5 09:40:47 ubutp kernel: [ 5286.230301] [] system_call_fastpath+0x1a/0x1f Apr 5 09:40:47 ubutp kernel: [ 5286.230304] ---[ end trace 103e9980ba77890b ]---