There's more stuff going on in my dmesg. Not sure if it helps, but anyway:

[ 9827.568968] ------------[ cut here ]------------
[ 9827.569058] WARNING: CPU: 2 PID: 1952 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:3324 intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]()
[ 9827.569062] Modules linked in: pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) dm_crypt rtsx_usb_ms memstick ax88179_178a usbnet mii btusb asus_nb_wmi uvcvideo videobuf2_vmalloc videobuf2_memops asus_wmi videobuf2_core sparse_keymap v4l2_common videodev media snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_intel snd_hda_controller kvm snd_hda_codec crct10dif_pclmul snd_usb_audio crc32_pclmul snd_usbmidi_lib snd_hwdep ghash_clmulni_intel snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi arc4 aesni_intel aes_x86_64 lrw gf128mul glue_helper iwldvm ablk_helper mac80211 cryptd rfcomm bnep bluetooth 6lowpan_iphc iwlwifi snd_seq joydev serio_raw snd_seq_device snd_timer lpc_ich cfg80211 snd soundcore
[ 9827.569140]  mei_me mei shpchp int3403_thermal binfmt_misc mac_hid parport_pc ppdev lp parport nls_iso8859_1 hid_generic usbhid hid ses enclosure rtsx_usb_sdmmc rtsx_usb uas usb_storage nouveau i915 mxm_wmi ttm i2c_algo_bit drm_kms_helper psmouse drm ahci libahci wmi video
[ 9827.569182] CPU: 2 PID: 1952 Comm: Xorg Tainted: G           OE 3.16.0-24-generic #32-Ubuntu
[ 9827.569186] Hardware name: ASUSTeK COMPUTER INC. UX32VD/UX32VD, BIOS UX32VD.212 09/17/2012
[ 9827.569190]  0000000000000009 ffff88029cbbfbf8 ffffffff8177fcbc 0000000000000000
[ 9827.569197]  ffff88029cbbfc30 ffffffff8106fd8d 0000000000000000 ffff88029fe1b000
[ 9827.569203]  ffff880035d88210 ffff88029be27000 ffff88029be27000 ffff88029cbbfc40
[ 9827.569209] Call Trace:
[ 9827.569226]  [<ffffffff8177fcbc>] dump_stack+0x45/0x56
[ 9827.569236]  [<ffffffff8106fd8d>] warn_slowpath_common+0x7d/0xa0
[ 9827.569244]  [<ffffffff8106fe6a>] warn_slowpath_null+0x1a/0x20
[ 9827.569291]  [<ffffffffc01efffc>] intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]
[ 9827.569303]  [<ffffffff810b9590>] ? prepare_to_wait_event+0x100/0x100
[ 9827.569346]  [<ffffffffc01f2ac3>] intel_crtc_disable_planes+0x33/0x1c0 [i915]
[ 9827.569386]  [<ffffffffc01f3090>] ironlake_crtc_disable+0x50/0x980 [i915]
[ 9827.569430]  [<ffffffffc00caf53>] ? drm_modeset_lock+0x33/0xf0 [drm]
[ 9827.569438]  [<ffffffff81785ab2>] ? mutex_lock+0x12/0x30
[ 9827.569479]  [<ffffffffc01f4457>] intel_crtc_update_dpms+0x67/0xa0 [i915]
[ 9827.569522]  [<ffffffffc01f8ac9>] intel_connector_dpms+0x59/0x70 [i915]
[ 9827.569559]  [<ffffffffc00c1e19>] drm_mode_obj_set_property_ioctl+0x399/0x3a0 [drm]
[ 9827.569593]  [<ffffffffc00c1e50>] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm]
[ 9827.569618]  [<ffffffffc00b0a4f>] drm_ioctl+0x1df/0x680 [drm]
[ 9827.569632]  [<ffffffff811f4bc8>] do_vfs_ioctl+0x2c8/0x4a0
[ 9827.569639]  [<ffffffff811e31a1>] ? __sb_end_write+0x31/0x60
[ 9827.569649]  [<ffffffff811e0d12>] ? vfs_write+0x1b2/0x1f0
[ 9827.569655]  [<ffffffff811f4e21>] SyS_ioctl+0x81/0xa0
[ 9827.569663]  [<ffffffff81787ced>] system_call_fastpath+0x1a/0x1f
[ 9827.569667] ---[ end trace a41706fd70b872ee ]---
[ 9828.321052] [drm:intel_dp_start_link_train] *ERROR* too many voltage retries, give up
[ 9833.866218] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20140424/nsarguments-95)
[ 9833.866460] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20140424/nsarguments-95)
[ 9833.867286] nouveau E[    PBUS][0000:01:00.0] MMIO write of 0x8000001f FAULT at 0x6013d4 [ !ENGINE ]