Comment 19 for bug 1384342

I'm running on an Intel Haswell i5-4670K and can confirm this happens intermittently without VT switching but it can often be be made to happen much more often by doing VT switches.

I'm running the lasest Utopic 3.16.0-24-generic #32-Ubuntu kernel on x86_64 and I've got a trace from syslog of this lock-up occuring twice in immediate succession:

Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348482] ------------[ cut here ]------------
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348519] WARNING: CPU: 2 PID: 2487 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:3324 intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]()
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348521] Modules linked in: webcamstudio(OE) videodev media dm_crypt pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) rfcomm bnep binfmt_misc hid_generic usbhid hid btusb bluetooth 6lowpan_iphc intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek kvm_intel kvm snd_hda_codec_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd serio_raw lpc_ich snd_hda_intel snd_hda_controller snd_hda_codec snd_seq_midi snd_hwdep snd_seq_midi_event snd_rawmidi snd_pcm shpchp mei_me snd_seq mei snd_seq_device snd_timer snd soc_button_array soundcore tpm_infineon mac_hid parport_pc ppdev it87 hwmon_vid lp parport mxm_wmi i915 psmouse i2c_algo_bit drm_kms_helper e1000e drm ahci ptp libahci pps_core wmi video
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348564] CPU: 2 PID: 2487 Comm: Xorg Tainted: G W IOE 3.16.0-24-generic #32-Ubuntu
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348566] Hardware name: Gigabyte Technology Co., Ltd. Z87X-D3H/Z87X-D3H-CF, BIOS F8 01/17/2014
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348567] 0000000000000009 ffff880420d5fc18 ffffffff8177fcbc 0000000000000000
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348570] ffff880420d5fc50 ffffffff8106fd8d 0000000000000000 ffff880428ff5000
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348573] ffff880423b88210 ffff880423938800 ffff880423938800 ffff880420d5fc60
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348576] Call Trace:
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348584] [<ffffffff8177fcbc>] dump_stack+0x45/0x56
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348589] [<ffffffff8106fd8d>] warn_slowpath_common+0x7d/0xa0
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348592] [<ffffffff8106fe6a>] warn_slowpath_null+0x1a/0x20
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348612] [<ffffffffc029cffc>] intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348617] [<ffffffff810b9590>] ? prepare_to_wait_event+0x100/0x100
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348634] [<ffffffffc029fac3>] intel_crtc_disable_planes+0x33/0x1c0 [i915]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348637] [<ffffffff81784e5b>] ? __ww_mutex_lock+0x1b/0xb0
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348653] [<ffffffffc02a0a17>] haswell_crtc_disable+0x57/0x2e0 [i915]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348656] [<ffffffff81785ab2>] ? mutex_lock+0x12/0x30
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348672] [<ffffffffc02a1457>] intel_crtc_update_dpms+0x67/0xa0 [i915]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348689] [<ffffffffc02a5ac9>] intel_connector_dpms+0x59/0x70 [i915]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348705] [<ffffffffc0186e19>] drm_mode_obj_set_property_ioctl+0x399/0x3a0 [drm]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348719] [<ffffffffc0186e50>] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348728] [<ffffffffc0175a4f>] drm_ioctl+0x1df/0x680 [drm]
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348734] [<ffffffff8121f9bc>] ? fsnotify+0x27c/0x350
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348737] [<ffffffff8121f9bc>] ? fsnotify+0x27c/0x350
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348741] [<ffffffff811f4bc8>] do_vfs_ioctl+0x2c8/0x4a0
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348744] [<ffffffff811e31a1>] ? __sb_end_write+0x31/0x60
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348747] [<ffffffff811e0d12>] ? vfs_write+0x1b2/0x1f0
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348750] [<ffffffff811f4e21>] SyS_ioctl+0x81/0xa0
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348754] [<ffffffff81787ced>] system_call_fastpath+0x1a/0x1f
Nov 2 16:51:38 jonathan-Z87X-D3H kernel: [ 3385.348755] ---[ end trace b767b96fc7b785f9 ]---
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518857] ------------[ cut here ]------------
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518881] WARNING: CPU: 1 PID: 5824 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:3324 intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]()
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518882] Modules linked in: webcamstudio(OE) videodev media dm_crypt pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) rfcomm bnep binfmt_misc hid_generic usbhid hid btusb bluetooth 6lowpan_iphc intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek kvm_intel kvm snd_hda_codec_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd serio_raw lpc_ich snd_hda_intel snd_hda_controller snd_hda_codec snd_seq_midi snd_hwdep snd_seq_midi_event snd_rawmidi snd_pcm shpchp mei_me snd_seq mei snd_seq_device snd_timer snd soc_button_array soundcore tpm_infineon mac_hid parport_pc ppdev it87 hwmon_vid lp parport mxm_wmi i915 psmouse i2c_algo_bit drm_kms_helper e1000e drm ahci ptp libahci pps_core wmi video
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518902] CPU: 1 PID: 5824 Comm: Xorg Tainted: G W IOE 3.16.0-24-generic #32-Ubuntu
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518903] Hardware name: Gigabyte Technology Co., Ltd. Z87X-D3H/Z87X-D3H-CF, BIOS F8 01/17/2014
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518903] 0000000000000009 ffff880373bffc18 ffffffff8177fcbc 0000000000000000
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518905] ffff880373bffc50 ffffffff8106fd8d 0000000000000000 ffff880428ff5000
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518906] ffff880423b88210 ffff880423938800 ffff880423938800 ffff880373bffc60
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518907] Call Trace:
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518912] [<ffffffff8177fcbc>] dump_stack+0x45/0x56
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518915] [<ffffffff8106fd8d>] warn_slowpath_common+0x7d/0xa0
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518917] [<ffffffff8106fe6a>] warn_slowpath_null+0x1a/0x20
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518925] [<ffffffffc029cffc>] intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518928] [<ffffffff810b9590>] ? prepare_to_wait_event+0x100/0x100
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518935] [<ffffffffc029fac3>] intel_crtc_disable_planes+0x33/0x1c0 [i915]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518937] [<ffffffff81784e5b>] ? __ww_mutex_lock+0x1b/0xb0
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518944] [<ffffffffc02a0a17>] haswell_crtc_disable+0x57/0x2e0 [i915]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518945] [<ffffffff81785ab2>] ? mutex_lock+0x12/0x30
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518952] [<ffffffffc02a1457>] intel_crtc_update_dpms+0x67/0xa0 [i915]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518960] [<ffffffffc02a5ac9>] intel_connector_dpms+0x59/0x70 [i915]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518969] [<ffffffffc0186e19>] drm_mode_obj_set_property_ioctl+0x399/0x3a0 [drm]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518974] [<ffffffffc0186e50>] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518979] [<ffffffffc0175a4f>] drm_ioctl+0x1df/0x680 [drm]
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518982] [<ffffffff8121f9bc>] ? fsnotify+0x27c/0x350
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518983] [<ffffffff8121f9bc>] ? fsnotify+0x27c/0x350
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518985] [<ffffffff811f4bc8>] do_vfs_ioctl+0x2c8/0x4a0
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518986] [<ffffffff811e31a1>] ? __sb_end_write+0x31/0x60
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518988] [<ffffffff811e0d12>] ? vfs_write+0x1b2/0x1f0
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518990] [<ffffffff811f4e21>] SyS_ioctl+0x81/0xa0
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518991] [<ffffffff81787ced>] system_call_fastpath+0x1a/0x1f
Nov 2 16:52:50 jonathan-Z87X-D3H kernel: [ 3456.518992] ---[ end trace b767b96fc7b785fa ]---

I'm going to give http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2014-11-01-vivid/ a go and report back what happens! :)