It starts with a WARNING in intel_crtc_wait_for_pending_flips() and then after a few very slow (tens of seconds) VT switches, in intel_display_power_put() Sep 18 06:20:00 tito kernel: [ 801.637835] ------------[ cut here ]------------ Sep 18 06:20:00 tito kernel: [ 801.637876] WARNING: CPU: 2 PID: 1386 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:3313 intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]() Sep 18 06:20:00 tito kernel: [ 801.637878] Modules linked in: xt_recent ctr ccm pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2 _common videodev btusb media hid_multitouch nvram dm_crypt arc4 ip6t_REJECT xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT xt_comment xt_LOG xt_limit xt_tcpudp joydev xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack intel_rapl x86_pkg_temp_thermal intel_powerclamp ip6table_filter ip6_tables coretemp nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrac k kvm_intel hid_rmi dell_wmi iptable_filter sparse_keymap kvm ip_tables x_tables iwlmvm mac80211 crct10dif_pclmul dell_laptop dcdbas snd_hda_codec_realtek snd_hda_codec_generic crc32_pclmul snd_hda_codec_hdm i ghash_clmulni_intel aesni_intel iwlwifi snd_hda_intel aes_x86_64 snd_hda_controller lrw snd_hda_codec gf128mul glue_helper ablk_helper snd_soc_rt5640 cryptd snd_hwdep snd_soc_rl6231 snd_soc_core cfg80211 s erio_raw snd_compress snd_pcm_dmaengine snd_pcm mei_me shpchp snd_seq_midi mei lpc_ich snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd snd_soc_sst_acpi dw_dmac soundcore i2c_hid dw_dmac_c ore i2c_designware_platform i2c_designware_core 8250_dw spi_pxa2xx_platform rfcomm bnep bluetooth 6lowpan_iphc mac_hid parport_pc ppdev lp parport hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper drm psmouse ahci libahci wmi video sdhci_acpi sdhci Sep 18 06:20:00 tito kernel: [ 801.637940] CPU: 2 PID: 1386 Comm: Xorg Tainted: G OE 3.16.0-14-generic #20-Ubuntu Sep 18 06:20:00 tito kernel: [ 801.637941] Hardware name: Dell Inc. XPS13 9333/0D13CR, BIOS A04 03/19/2014 Sep 18 06:20:00 tito kernel: [ 801.637943] 0000000000000009 ffff880036543c18 ffffffff817793ae 0000000000000000 Sep 18 06:20:00 tito kernel: [ 801.637945] ffff880036543c50 ffffffff8106fced 0000000000000000 ffff88020cbfb000 Sep 18 06:20:00 tito kernel: [ 801.637947] ffff88020c488240 ffff88020c8bd800 ffff88020c8bd800 ffff880036543c60 Sep 18 06:20:00 tito kernel: [ 801.637950] Call Trace: Sep 18 06:20:00 tito kernel: [ 801.637957] [] dump_stack+0x45/0x56 Sep 18 06:20:00 tito kernel: [ 801.637961] [] warn_slowpath_common+0x7d/0xa0 Sep 18 06:20:00 tito kernel: [ 801.637964] [] warn_slowpath_null+0x1a/0x20 Sep 18 06:20:00 tito kernel: [ 801.637983] [] intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915] Sep 18 06:20:00 tito kernel: [ 801.637987] [] ? prepare_to_wait_event+0x100/0x100 Sep 18 06:20:00 tito kernel: [ 801.638005] [] intel_crtc_disable_planes+0x33/0x1c0 [i915] Sep 18 06:20:00 tito kernel: [ 801.638007] [] ? __ww_mutex_lock+0x1b/0xb0 Sep 18 06:20:00 tito kernel: [ 801.638024] [] haswell_crtc_disable+0x57/0x2e0 [i915] Sep 18 06:20:00 tito kernel: [ 801.638026] [] ? mutex_lock+0x12/0x30 Sep 18 06:20:00 tito kernel: [ 801.638043] [] intel_crtc_update_dpms+0x67/0xa0 [i915] Sep 18 06:20:00 tito kernel: [ 801.638061] [] intel_connector_dpms+0x59/0x70 [i915] Sep 18 06:20:00 tito kernel: [ 801.638079] [] drm_mode_obj_set_property_ioctl+0x399/0x3a0 [drm] Sep 18 06:20:00 tito kernel: [ 801.638092] [] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm] Sep 18 06:20:00 tito kernel: [ 801.638102] [] drm_ioctl+0x1df/0x680 [drm] Sep 18 06:20:00 tito kernel: [ 801.638108] [] ? __enqueue_entity+0x78/0x80 Sep 18 06:20:00 tito kernel: [ 801.638111] [] ? __switch_to_xtra+0x13f/0x170 Sep 18 06:20:00 tito kernel: [ 801.638114] [] do_vfs_ioctl+0x2c8/0x4a0 Sep 18 06:20:00 tito kernel: [ 801.638117] [] ? __schedule+0x39d/0x890 Sep 18 06:20:00 tito kernel: [ 801.638119] [] SyS_ioctl+0x81/0xa0 Sep 18 06:20:00 tito kernel: [ 801.638122] [] system_call_fastpath+0x1a/0x1f Sep 18 06:20:00 tito kernel: [ 801.638124] ---[ end trace ec27fd2563ff929d ]--- Sep 18 05:59:57 tito kernel: [46236.672315] ------------[ cut here ]------------ Sep 18 05:59:57 tito kernel: [46236.672374] WARNING: CPU: 0 PID: 1437 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_pm.c:5997 intel_display_power_put+0x14c/0x160 [i915]() Sep 18 05:59:57 tito kernel: [46236.672377] Modules linked in: ctr ccm pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media btusb hid_multitouch nvram dm_crypt joydev ip6t_REJECT xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT xt_comment xt_LOG xt_limit xt_tcpudp xt_addrtype arc4 intel_rapl nf_conntrack_ipv4 nf_defrag_ipv4 x86_pkg_temp_thermal xt_conntrack intel_powerclamp coretemp ip6table_filter ip6_tables kvm_intel nf_conntrack_netbios_ns hid_rmi nf_conntrack_broadcast nf_nat_ftp nf_nat dell_wmi nf_conntrack_ftp sparse_keymap nf_conntrack kvm iptable_filter ip_tables x_tables crct10dif_pclmul crc32_pclmul dell_laptop dcdbas ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd iwlmvm mac80211 snd_hda_codec_realtek serio_raw snd_hda_codec_generic iwlwifi cfg80211 rfcomm snd_hda_codec_hdmi bnep bluetooth lpc_ich 6lowpan_iphc shpchp mei_me snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep mei snd_soc_rt5640 snd_soc_rl6231 snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_seq_midi snd_seq_midi_event dw_dmac dw_dmac_core 8250_dw snd_rawmidi snd_soc_sst_acpi snd_seq snd_seq_device snd_timer snd i2c_hid soundcore i2c_designware_platform spi_pxa2xx_platform i2c_designware_core mac_hid parport_pc ppdev lp parport hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper psmouse drm ahci wmi libahci video sdhci_acpi sdhci Sep 18 05:59:57 tito kernel: [46236.672493] CPU: 0 PID: 1437 Comm: Xorg Tainted: G W OE 3.16.0-14-generic #20-Ubuntu Sep 18 05:59:57 tito kernel: [46236.672496] Hardware name: Dell Inc. XPS13 9333/0D13CR, BIOS A04 03/19/2014 Sep 18 05:59:57 tito kernel: [46236.672499] 0000000000000009 ffff8802101dfaf8 ffffffff817793ae 0000000000000000 Sep 18 05:59:57 tito kernel: [46236.672504] ffff8802101dfb30 ffffffff8106fced ffff88020cab002c 000000000000000b Sep 18 05:59:57 tito kernel: [46236.672509] ffff88020cab8550 ffff88020fda5000 ffff88020cab0000 ffff8802101dfb40 Sep 18 05:59:57 tito kernel: [46236.672513] Call Trace: Sep 18 05:59:57 tito kernel: [46236.672526] [] dump_stack+0x45/0x56 Sep 18 05:59:57 tito kernel: [46236.672535] [] warn_slowpath_common+0x7d/0xa0 Sep 18 05:59:57 tito kernel: [46236.672540] [] warn_slowpath_null+0x1a/0x20 Sep 18 05:59:57 tito kernel: [46236.672567] [] intel_display_power_put+0x14c/0x160 [i915] Sep 18 05:59:57 tito kernel: [46236.672606] [] modeset_update_crtc_power_domains+0x204/0x210 [i915] Sep 18 05:59:57 tito kernel: [46236.672643] [] haswell_modeset_global_resources+0xe/0x10 [i915] Sep 18 05:59:57 tito kernel: [46236.672678] [] __intel_set_mode+0x5fa/0xab0 [i915] Sep 18 05:59:57 tito kernel: [46236.672714] [] intel_set_mode+0x16/0x30 [i915] Sep 18 05:59:57 tito kernel: [46236.672749] [] intel_crtc_set_config+0xa4a/0xda0 [i915] Sep 18 05:59:57 tito kernel: [46236.672780] [] drm_mode_set_config_internal+0x61/0xe0 [drm] Sep 18 05:59:57 tito kernel: [46236.672808] [] drm_mode_setcrtc+0x283/0x580 [drm] Sep 18 05:59:57 tito kernel: [46236.672827] [] drm_ioctl+0x1df/0x680 [drm] Sep 18 05:59:57 tito kernel: [46236.672840] [] do_vfs_ioctl+0x2c8/0x4a0 Sep 18 05:59:57 tito kernel: [46236.672845] [] ? __sb_end_write+0x31/0x60 Sep 18 05:59:57 tito kernel: [46236.672851] [] ? vfs_write+0x1b2/0x1f0 Sep 18 05:59:57 tito kernel: [46236.672856] [] SyS_ioctl+0x81/0xa0 Sep 18 05:59:57 tito kernel: [46236.672861] [] system_call_fastpath+0x1a/0x1f Sep 18 05:59:57 tito kernel: [46236.672864] ---[ end trace 9b468c36efd27191 ]--- Sep 18 05:59:57 tito kernel: [46236.672867] ------------[ cut here ]------------