/var/log/dmesg

[    8.205595] HDMI status: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=0
[    8.205667] input: HD-Audio Generic HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input7
[    8.207372] mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
[    8.207373] [drm] MTRR allocation failed.  Graphics performance may suffer.
[    8.207541] i915 0000:00:02.0: irq 44 for MSI/MSI-X
[    8.207545] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
[    8.207546] [drm] Driver supports precise vblank timestamp query.
[    8.214648] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
[    8.305202] [drm:pch_irq_handler] *ERROR* PCH poison interrupt