Comment 10 for bug 1406982

Kernel info - Linux gurvinder-I1525 3.13.11-031311ckt13-generic #201412181938 SMP Thu Dec 18 19:40:21 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Following is what has happened.
After kernel installation when OS is booted, below message is there in dmesg

   77.202640] WARNING: CPU: 1 PID: 1473 at /home/apw/COD/linux/drivers/gpu/drm/i915/intel_display.c:9235 check_encoder_state+0x215/0x270 [i915]()
[ 77.202642] encoder's hw state doesn't match sw tracking (expected 0, found 1)
[ 77.202644] Modules linked in: ctr ccm rfcomm bnep bluetooth binfmt_misc snd_hda_codec_idt snd_hda_codec_hdmi uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev arc4 iwl3945 snd_hda_intel iwlegacy snd_hda_codec mac80211 snd_hwdep snd_pcm i915 snd_page_alloc dell_wmi cfg80211 gpio_ich snd_seq_midi dell_laptop snd_seq_midi_event sparse_keymap dcdbas snd_rawmidi r852 snd_seq sm_common nand snd_seq_device dm_multipath coretemp nand_ecc snd_timer scsi_dh nand_bch drm_kms_helper snd bch joydev serio_raw nand_ids mtd drm soundcore parport_pc r592 i2c_algo_bit ppdev memstick lp lpc_ich parport video wmi mac_hid hid_generic usbhid hid psmouse firewire_ohci sdhci_pci sdhci ahci firewire_core libahci crc_itu_t sky2
[ 77.202705] CPU: 1 PID: 1473 Comm: Xorg Tainted: G W 3.13.11-031311ckt13-generic #201412181938
[ 77.202707] Hardware name: Dell Inc. Inspiron 1525 /0WP007, BIOS A17 10/27/2009
[ 77.202709] 0000000000002413 ffff8800a4df99a8 ffffffff81748f75 0000000000000007
[ 77.202713] ffff8800a4df99f8 ffff8800a4df99e8 ffffffff81069adc ffff8800ad3ee800
[ 77.202717] ffff8800ad3ee800 ffff8800ad3d82f8 0000000000000001 ffff8800ad3d8000
[ 77.202722] Call Trace:
[ 77.202726] [<ffffffff81748f75>] dump_stack+0x46/0x58
[ 77.202730] [<ffffffff81069adc>] warn_slowpath_common+0x8c/0xc0
[ 77.202734] [<ffffffff81069bc6>] warn_slowpath_fmt+0x46/0x50
[ 77.202755] [<ffffffffa0315535>] check_encoder_state+0x215/0x270 [i915]
[ 77.202777] [<ffffffffa0327e5d>] intel_modeset_check_state+0x5d/0xa0 [i915]
[ 77.202799] [<ffffffffa0327ec5>] intel_set_mode+0x25/0x30 [i915]
[ 77.202820] [<ffffffffa03282b5>] intel_release_load_detect_pipe+0xd5/0x100 [i915]
[ 77.202848] [<ffffffffa0350503>] intel_tv_detect+0x163/0x210 [i915]
[ 77.202856] [<ffffffffa01a1293>] drm_helper_probe_single_connector_modes+0x203/0x3a0 [drm_kms_helper]
[ 77.202873] [<ffffffffa012656c>] drm_mode_getconnector+0x41c/0x460 [drm]
[ 77.202886] [<ffffffffa0116e3a>] drm_ioctl+0x4da/0x600 [drm]
[ 77.202891] [<ffffffff8107d595>] ? set_current_blocked+0x15/0x20
[ 77.202907] [<ffffffffa0126150>] ? drm_mode_getcrtc+0xe0/0xe0 [drm]
[ 77.202911] [<ffffffff8107a04f>] ? recalc_sigpending+0x1f/0x60
[ 77.202915] [<ffffffff811dae85>] do_vfs_ioctl+0x75/0x2c0
[ 77.202919] [<ffffffff8107e339>] ? restore_altstack+0x19/0x30
[ 77.202922] [<ffffffff811db161>] SyS_ioctl+0x91/0xb0
[ 77.202926] [<ffffffff8175e52d>] system_call_fastpath+0x1a/0x1f
[ 77.202929] ---[ end trace 0c25a76bfe32ddde ]---

I played 720p mkv format video without any issues. However when i played Youtube video in chrome LCD screen goes black.
At this point you cannot do anything, As mentioned by Owens, i closed laptop lid (Did not do proper shutdown). System goes off, then Open lid again. Display back with another warning message mentioned below.

[ 331.245954] WARNING: CPU: 0 PID: 1473 at /home/apw/COD/linux/drivers/gpu/drm/i915/intel_display.c:9235 check_encoder_state+0x215/0x270 [i915]()
[ 331.245957] encoder's hw state doesn't match sw tracking (expected 0, found 1)
[ 331.245960] Modules linked in: ctr ccm rfcomm bnep bluetooth binfmt_misc snd_hda_codec_idt snd_hda_codec_hdmi uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev arc4 iwl3945 snd_hda_intel iwlegacy snd_hda_codec mac80211 snd_hwdep snd_pcm i915 snd_page_alloc dell_wmi cfg80211 gpio_ich snd_seq_midi dell_laptop snd_seq_midi_event sparse_keymap dcdbas snd_rawmidi r852 snd_seq sm_common nand snd_seq_device dm_multipath coretemp nand_ecc snd_timer scsi_dh nand_bch drm_kms_helper snd bch joydev serio_raw nand_ids mtd drm soundcore parport_pc r592 i2c_algo_bit ppdev memstick lp lpc_ich parport video wmi mac_hid hid_generic usbhid hid psmouse firewire_ohci sdhci_pci sdhci ahci firewire_core libahci crc_itu_t sky2
[ 331.246037] CPU: 0 PID: 1473 Comm: Xorg Tainted: G W 3.13.11-031311ckt13-generic #201412181938
[ 331.246040] Hardware name: Dell Inc. Inspiron 1525 /0WP007, BIOS A17 10/27/2009
[ 331.246042] 0000000000002413 ffff8800a4df99a8 ffffffff81748f75 0000000000000007
[ 331.246048] ffff8800a4df99f8 ffff8800a4df99e8 ffffffff81069adc ffff8800ad3ee800
[ 331.246052] ffff8800ad3ee800 ffff8800ad3d82f8 0000000000000001 ffff8800ad3d8000
[ 331.246056] Call Trace:
[ 331.246066] [<ffffffff81748f75>] dump_stack+0x46/0x58
[ 331.246073] [<ffffffff81069adc>] warn_slowpath_common+0x8c/0xc0
[ 331.246077] [<ffffffff81069bc6>] warn_slowpath_fmt+0x46/0x50
[ 331.246098] [<ffffffffa0315535>] check_encoder_state+0x215/0x270 [i915]
[ 331.246121] [<ffffffffa0327e5d>] intel_modeset_check_state+0x5d/0xa0 [i915]
[ 331.246143] [<ffffffffa0327ec5>] intel_set_mode+0x25/0x30 [i915]
[ 331.246165] [<ffffffffa03282b5>] intel_release_load_detect_pipe+0xd5/0x100 [i915]
[ 331.246195] [<ffffffffa0350503>] intel_tv_detect+0x163/0x210 [i915]
[ 331.246205] [<ffffffffa01a1293>] drm_helper_probe_single_connector_modes+0x203/0x3a0 [drm_kms_helper]
[ 331.246231] [<ffffffffa012656c>] drm_mode_getconnector+0x41c/0x460 [drm]
[ 331.246245] [<ffffffffa0116e3a>] drm_ioctl+0x4da/0x600 [drm]
[ 331.246262] [<ffffffffa0126150>] ? drm_mode_getcrtc+0xe0/0xe0 [drm]
[ 331.246268] [<ffffffff811dae85>] do_vfs_ioctl+0x75/0x2c0
[ 331.246271] [<ffffffff811db161>] SyS_ioctl+0x91/0xb0
[ 331.246276] [<ffffffff8175e52d>] system_call_fastpath+0x1a/0x1f
[ 331.246279] ---[ end trace 0c25a76bfe32de21 ]---
[ 337.970971] perf samples too long (2531 > 2500), lowering kernel.perf_event_max_sample_rate to 50000

I was running 3.17 kernel before and using that kernel I used to warning message in dmesg but screen never goes black.