DP is the acronym for display port. VIA chipset VX900 starts to support DP devices.

The support combination of DP depends on the capability of mother boards. Some support the DP muxed with internal HDMI while others don't.

The DP muxed with internal HDMI is connected through the DP slot on board. The DP muxed with PCI-E is connected through a PCI-E card as DP adapter.

All the following options belong to the DP's or DP-2's Monitor section. The identifier DP presents the DP muxed with internal HDMI, while the identifier DP-2 presents the DP muxed with PCI-E.

Basic Configuration

You may start from the basic options defined by Xorg.

Option       "Enable"                   "boolean"
Option       "Disable"                 "boolean"
Option       "Ignore"                    "boolean"
Option       "PreferredMode"    "string"
Option       "Position"                 "integer integer"
Option       "Rotate"                    "string"
Option       "LeftOf" ("RightOf", "Below", "Above")          "string"
Option       "MinClock"               "integer"
Option       "MaxClock"              "integer"

The following three options are exclusive, you can use only one or none. If none is set, X takes "enable" by default.

Option      "Enable"               "boolean" 
Option      "Disable"              "boolean" 
Option      "Ignore"                 "boolean"

Option "Enable" "boolean"

It means to light the DP when starting X.

Option "Disable" "boolean"

It means not to light the DP when starting X, but you could light it by the command "$ xrandr  --auto".

Option "Ignore" "boolean"

X will not create the output for the DP. You could not light it dynamically by any means.

Option "PreferredMode" "string"

It set the display mode which would apply to DP, say "1024x768". Note that if the display device is disabled, you may not add this option. Otherwise, that display device could be lighted when X starts up. The supported mode is up to 2048x1536.

Option "Position" "integer integer"

Set the start posotion of the output. The integers represents the position by two coordinates (x,y). The default value is "0 0". This option takes effect when two display devices are enabled. It makes no difference if only one is enabled.

Option "Rotate" "string"

Rotate the output of the display device. The valid string could be left, right, normal, inverted, and the corresponding rotation degree is 270, 90, 0, 180 (CW). The default value is normal. To enable HW rotation, get more information from Chapter 6. Configuring Hardware rotation

Option "LeftOf"      "string"
Option "RightOf"    "string"
Option "Below"      "string"
Option "Above"      "string"

Enable the extend mode. If this option is not set when two display devices are enabled, the display mode would be clone mode. The string after the operator is one of the display device you intend to light. However, it's forbidden to use this option when only one display device is enabled.

Option "MinClock"    "integer"
Option "MaxClock"   "integer"

Put constrains to the display device, in order to filter out some mode. Unit: Hz.

DP related options

Option "Hotplug"

This options is used to support hot-plug function and change mode on the fly. But it will cost CPU usage.

Option "NoDDCValue" "boolean"

This option is used when the display device's EDID is broken, but you strongly intend to light the device. It is not recommended to use, because the display device can be damaged. And when using this option, it's better to set modeline. Because in this case, device's modelist only includes the Xorg default modes, which are limited and may not have your desired mode.

Note that to avoid DI port conflicts, it's better to ignore the display devices which are not to be used.

You can get a complete sample in Appendix D. X Config Sample (Using the XRandR Extension).