[20776.268338] WARNING: CPU: 0 PID: 2579 at /build/linux-Mxzr_W/linux-3.13.0/drivers/gpu/drm/i915/intel_display.c:9245 intel_modeset_check_state+0x62d/0x780 [i915]()
[20776.268344] encoder's hw state doesn't match sw tracking (expected 1, found 0)
[20776.268348] Modules linked in: md4 pci_stub vboxpci(OX) vboxnetadp(OX) vboxnetflt(OX) vboxdrv(OX) ctr ccm rfcomm bnep bluetooth binfmt_misc nls_utf8 cifs fscache snd_hda_codec_idt gpio_ich dell_wmi sparse_keymap coretemp dell_laptop dcdbas kvm_intel arc4 kvm snd_hda_intel snd_hda_codec snd_hwdep iwl3945 snd_pcm iwlegacy snd_page_alloc joydev serio_raw snd_seq_midi snd_seq_midi_event mac80211 snd_rawmidi lpc_ich snd_seq r852 cfg80211 sm_common nand r592 snd_seq_device snd_timer nand_ecc memstick nand_bch bch snd parport_pc nand_ids mtd ppdev i915 shpchp soundcore lp drm_kms_helper parport drm i2c_algo_bit mac_hid wmi video hid_generic usbhid hid psmouse firewire_ohci ahci b44 libahci sdhci_pci sdhci pata_acpi firewire_core ssb mii crc_itu_t
[20776.268491] CPU: 0 PID: 2579 Comm: upowerd Tainted: G        W  OX 3.13.0-85-generic #129-Ubuntu
[20776.268496] Hardware name: Dell Inc. Inspiron 1720                   /0UK439, BIOS A09 07/11/2008
[20776.268502]  0000000000000000 ffff8800b1a33b68 ffffffff8172b6a7 ffff8800b1a33bb0
[20776.268512]  0000000000000009 ffff8800b1a33ba0 ffffffff810699cd ffff8800b1a33c20
[20776.268520]  0000000000000001 ffff8800d5914800 ffff8800d5914af8 ffff8800c3c66400
[20776.268529] Call Trace:
[20776.268545]  [<ffffffff8172b6a7>] dump_stack+0x64/0x82
[20776.268555]  [<ffffffff810699cd>] warn_slowpath_common+0x7d/0xa0
[20776.268564]  [<ffffffff81069a3c>] warn_slowpath_fmt+0x4c/0x50
[20776.268618]  [<ffffffffa01ac90d>] intel_modeset_check_state+0x62d/0x780 [i915]
[20776.268671]  [<ffffffffa01acaf5>] intel_set_mode+0x25/0x30 [i915]
[20776.268722]  [<ffffffffa01acbc6>] intel_release_load_detect_pipe+0xc6/0xf0 [i915]
[20776.268781]  [<ffffffffa01d4d49>] intel_tv_detect+0x359/0x500 [i915]
[20776.268829]  [<ffffffffa00fbede>] status_show+0x3e/0x80 [drm]
[20776.268842]  [<ffffffff8149b270>] dev_attr_show+0x20/0x60
[20776.268852]  [<ffffffff81731f82>] ? mutex_lock+0x12/0x2f
[20776.268861]  [<ffffffff812386ef>] sysfs_seq_show+0x11f/0x240
[20776.268871]  [<ffffffff811e561a>] seq_read+0xea/0x370
[20776.268881]  [<ffffffff811c18e5>] vfs_read+0x95/0x160
[20776.268889]  [<ffffffff811c23f9>] SyS_read+0x49/0xa0
[20776.268898]  [<ffffffff8173c39d>] system_call_fastpath+0x1a/0x1f