DisplayPort

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Revision as of 03:12, 27 November 2011 by Aculich (Talk | contribs) (added NVidia Optimus disabling info for T420(s))
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DisplayPort is a digital video connector, available on select ThinkPads

ThinkPads featuring this technology

Port Replicators and Docks featuring this technology

Note, some have multiple Displayports

DVI Pass-through

Certain ThinkPad models have a DisplayPort connection which offers DVI pass-through.

Check ThinkPad Digital Video Interface (DVI) and DVI Pass-Through for more information, and to see if a specific model and configuration is supported.

Audio Support

There are reports that DisplayPort on some (possibly all) current thinkpads does not support audio. While there are adapters to convert DisplayPort to HDMI, the lack of audio makes it impossible to, for example, watch a DVD or Blu-Ray on an HDTV using the DisplayPort. See this thread for more information

Audio over DisplayPort when used in conjunction with a DisplayPort to HDMI conversion cable is confirmed to work on W500, T410 and T510 both on integrated and discrete graphics options on Windows systems.

T410s

The T410s supports audio pass-through via DisplayPort on recent Linux systems.

With the Intel HD Audio modul selected recent linux kernels detect the DisplayPort audio as a separate output device:

On 2.6.36-rc1 the following devices can be found in /proc/asound/*

 Codec: Intel IbexPeak HDMI
 Device: name="INTEL HDMI 0", type="HDMI", device=3
 Device: name="INTEL HDMI 1", type="HDMI", device=7

If you want to pass Audio via DisplayPort you just have to switch to the Intel HDMI audio output device for the application in PulseAudio (didn't test with pure ALSA).

W510

The more recent versions of the W510 with the Quadro FX 880M support audio and video out through DisplayPort. Tested with a DisplayPort to HDMI with Audio converter. Used alsa (no PulseAudio) and mplayer, 2.6.35-ARCH, using mplayer -afm hwdts,hwac3 -ao alsa:noblock:device=hw=1.7 and nvidia driver version 256.53. Had to unmute with alsamixer -c1

Problems

T420s

The BIOS for the T420s (and presumably also the T420) settings for _Graphics Device_ default to NVIDIA Optimus and the OS Detection for NVIDIA Optimus is set to Disabled which is not a good set of defaults for Linux since Optimus is only supported by Windows 7. To get the NVidia drivers working for Linux I had to set the Graphics Device to Discrete Graphics. This was as of 2011-11-26 using driver version 290.10. Then run sudo nvidia-xconfig. Both TwinView and Xinerama worked fine.

Twinview using Displayport and DVI broken

On my T410 mini-dock series 3, the displayport works unless I try to use it while using the DVI out as well. DVI+VGA works, but nvidia-settings dies horribly. Tried with 195.* and 260* drivers.

I am using a displayport -> DVI adapter (displayport++ allows this).

FIX: Using Nouveau drivers instead of the nvidia binary blob allows my displayport to work in concert with the DVI out of my dock. This allows dual digital external displays. Attempting to activate the laptop monitor as well leads to problems.

ANOTHER FIX: Version 275* from the nvidia website allows me to use Displayport and DVI at the same time as well.

External Sources