Supported Panel Size

480x640, 640x480, 800x480, 800x600, 1024x600, 1024x768, 1280x768, 1280x800, 1280x1024, 1360x768, 1366x768, 1400x1050, 1440x900, 1600x1200

Internal LCD configuration

For internal LCD, you need to confirm the LCD is configured to be the active display device.

The default value of LCDPort depends on which VIA chipset you use. And if the LCD panel could not be enabled by the default setting, you need specify the internal LCD port using the following option.

Option "LCDPort" "LVDS0" (or "LVDS1" , "LVDS0LVDS1")

LVDS0/LVDS1 is for single-channel LCD panel.
LVDS0LVDS1 is for dual-channel LCD panel. For dual-channel LCD panel, another option "DualChannel" is mandatory.

For example,

Section "Device"
       Driver   "via"
       VendorName  "VIA Tech"
       BoardName   "via"
       Identifier  "Device0"
       Option "ActiveDevice" "LCD"
       Option "LCDPort" "LVDS0"
       Screen 0 
EndSection

External LCD configuration

The configuration for external LCD is almost the same as the internal LCD, but the value for LCDPort is different. The external LCD could be connected through external LVDS transmitter, i.e. VT1636.

The default value of LCDPort depends on which VIA chipset you use. And if the LCD panel could not be enabled by the default setting, you need specify the external LCD port using the following option.
Option "LCDPort" "DVP1" (or "DFP_HIGH", "DFP_LOW" , "DFP_HIGHLOW" , "DVP0")

Or 18bits TTL panel, for external TTL,
Option "LCDPort" "TTL"

DVP represents "Digital Visual Port".
DFP represents "Digital Flat Panel Port". They are all physical interfaces.

Each of DVP0 and DVP1 is a 12-bit digital port.
DFP is a 24-bit digitial port, but can be devided into two 12-bit digital ports, DFP_LOW and DFP_HIGH.
Generally, single-channel LCD panels use 12-bit digital port, while dual-channel LCD panels use 24-bit digital port. For dual-channel LCD panel, another option "DualChannel" is mandatory.

For example,

Section "Device"
       Driver   "via"
       VendorName  "VIA Tech"
       BoardName   "via"
       Identifier  "Device0"
       Option   "ActiveDevice" "LCD"
       Option   "LCDPort" "DVP1"
       Screen 0 
EndSection

Two LCDs configuration

To light two LCD panels, you need set both LCD panels to be the active display devices.

The default value of LCDPort depends on situation. If the LCD panels could not be enabled by the default setting, you need specify the LCD port using the following option.

Option "LCDPort" "LVDS0LVDS1" (or "LVDS1DVP1")

For the combination of two internal LCD panels, the default value of LCDPort is LVDS0LVDS1. There's no need to set it. But you need confirm the hardware has the capability to support two internal LCD panels.

For the combination of one internal LCD panel and one external LCD panel, the default value of LCDPort is LVDS0DVP1. If the LCD panels are connected to the right port, you should not set the LCDPort option. Otherwise, please try to sepecify the LCDPort to be LVDS1DVP1. For example,

Section "Device"
       Driver   "via"
       VendorName  "VIA Tech"
       BoardName   "via"
       Identifier  "Device0"
       Option  "ActiveDevice" "LCD, LCD2"
       Option  "LCDPort" "LVDS1DVP1"       
       # Add this option only when internal LCD is connected to LVDS1, and external LCD is connected to DVP1.
       Screen 0 
EndSection

This release does not support the combination of two external LCD panels.

Note that, to light the combination of two LCD panels, the two panels should have the same size.

LCD Related Options

Despite internal or external LCD, there are some specified options for LCD configuration. All the following options belong to the Section "Device".

Option "Center"

Display in the center of the LCD panel when the mode is smaller than native mode. Without this option, LCD display is expanding.

Option "PanelSize" "string"

Manually set the LCD panel's physical size. Legal values are listed in supported list. Usually, this option is used to specify the LCD panel's resolution when the driver fails to read its EDID. Get more information about EDID from Part III. Chapter 6. Light the Display Device by EDID.

Option "DualChannel" "string"

This is an option to configure dual-channel LCD panel. The default value is related to the PanelSize settings. But you can use this option to override the default value. The valid values are "TRUE", "True", "true" or "FALSE", "False", "false".

Option "NoDithering" "boolean"

Dithering is a technique used in computer graphics to create the illusion of color depth in images with a limited color palette (color quantization). Some LCD panels apply this technique while other don't. If the LCD panel is not a dithering panel, set the value to be "True". Without this option, the VIA driver takes it a dithering panel by default.

Option "LCD_MSB_ENABLE" "boolean"

This option is relative to LVDS output bit order. Input data from graphic DI port to LVDS is LSB. If you use a MSB panel, set the value to be "True". LVDS will convert the data stream from LSB to MSB. The default order is LSB.

Option "ForceLCD" "boolean"

Remove the BIOS dependency when set the value to be "True", that is LCD panel could be lighted even it is disabled in BIOS settings.