The following options are supported by the VIA accelerated Linux graphics driver. Most of them are demonstrated in the chapters from part III to part V. Here presents the quick index for the options. Whether using XRandR extension makes some differences to the dirver options.
Index of contents:
Driver Options when not using the XRandR Extension
Section "Device"
Option "ActiveDevice" "string1 [, string2]"
Specify the display devices that you intend to light. The VIA driver supports two CRTCs, thus supports two display devices at the most. Valid values are "CRT", "LCD", "DVI", "HDMI", "TV". If lighting two display devices, valid values are any arbitral combination of the two. But if the two display devices are of the same type, the valid values are "CRT, CRT2", "LCD, LCD2", "TV, TV2". In Duo-view mode, the former is the primary display device and the latter is the secondary. After all, the combinations depend on specified chipset.
Option "Refresh" "integer"
This option set the refresh rate, which is the number of times in a second that display hardware draws the data it is being given. Increasing the refresh rate decreases flickering, thereby reducing eye strain. However, if a refresh rate is specified that is beyond what is recommended for the display, damage to the display can occur. This option applies to CRT and DVI.
Option "LCDPort" "string"
Specify the DI port for a LCD panel. Valid values are "LVDS0", "LVDS1" , "LVDS0LVDS1", "DVP0", "DVP1", "DFP_HIGH", "DFP_LOW", "DFP_HIGHLOW", "TTL".
Option "ForceLCD" "boolean"
Remove the BIOS dependency of a LCD panel. It can apply to both internal and external LCD panels.
Option "Center"
Display in the center of the LCD panel when current 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.
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.
Option "DVIPort" "string"
Specify the DI port for a DVI. Valid values are "DVP0", "DVP1", "DFP_HIGH", "DFP_LOW".
Option "TVPort" "string"
Specify the DI port for a TV. Valid values are "DVP0", "DVP1".
Option "TVType" "string"
Specify the TV standard. Valid values are "NTSC", "PAL", "480P", "576P", "720P", "1080I".
Option "TVOutput" "string"
Specify the format of TV output signal. Valid values are "Composite", "S-Video", "RGB", "YCbCr", "YPbPr", "SC", "RGBSC", "YCbCrSC", "YPbPrSC".
Option "TV2Type" "string"
Apply this option when lighting two TVs, to specify the TV standard for the second TV. Valid values are "NTSC", "PAL", "480P", "576P", "720P", "1080I".
Option "TV2Output" "string"
Apply this option when lighting two TVs, to specify the output signal format for the second TV. Valid values are "Composite", "S-Video", "RGB", "YCbCr", "YPbPr", "SC", "RGBSC", "YCbCrSC", "YPbPrSC".
Option "NoDDCValue"
Force to light display device by built-in timing, without fetching EDID from the display device. It is not recommended to use this option. The display device can be damaged.
Option "DISPLAY_3DScaling_LCD" "boolean"
Enable 3D Scaling for LCD.
Option "DISPLAY_3DScaling_HDMI" "boolean"
Enable 3D Scaling for HDMI
Option "DISPLAY_3DScaling_TV" "boolean"
Enable 3D Scaling for TV/HDTV.
Option "Rotate" "string"
Rotate the screen in 90 degree increments. Valid values are "CW", "UD", "CCW", which stands for 90, 180, 270 degree respectively.
Option "RotateType" "string"
Use hardware acceleration when rotating the screen. The valid values are "HW", "SW". If set to "SW", the rotation is done by the main CPU.
Option "AccelMethod" "EXA"
Enable EXA architecture.
Option "SWCursor" "boolean"
Set the software cursor.
Option "DPASetting_DVP0" "int1, int2, int3"
This option is to adjust the clock of DVP0. Int1 ranges from 0 to 15, int2/int3 ranges from 0 to 3.
Option "DPASetting_DVP1" "int1, int2, int3"
This option is to adjust the clock of DVP1. Int1 ranges from 0 to 15, int2/int3 ranges from 0 to 3.
Option "DPASetting_DFPHIGH" "integer"
This option is to adjust the clock of DFP High. The value ranges from 0 to 15.
Option "DPASetting_DFPLOW" "integer"
This option is to adjust the clock of DFP Low. The value ranges from 0 to 15.
Option "DPASetting_VT1636" "int1, int2 "
This option is to adjust the clock of the LVDS transmitter VT1636. Int1 ranges from 0 to 31, and int2 ranges from 0 to 15.
Option "VideoOnDevice" "string"
Special option for VIA chipset CN700. The reason is CN700 has only one overlay engine. This option decides the video shows on which display device. The valid string is one of the enabled display devices.
Option "DRI" "boolean"
This option allows to disable DRI module. The default value is true.
Section "Extensions"
Option "Composite" "boolean"
Set to use the composite extension.
Driver Options when using the XRandR Extension
Section "Monitor"
Option "Type" "string"
This option specifies in which way the display device is connected to the board. Valid types are External, Internal, HardWired, TTL. External means the display device is connected via external transmitter/encoder. Internal means the display device is connected via internal transmitter/encoder. HardWired is used when the display device is connected via VT1634 or VT1637. TTL is used when connecting TTL panel. The default type is Internal.
Option "DIPort" "string"
This option specifies which digital port is occupied by the display device. Valid ports are DFP_HIGH, DFP_LOW, DFP_HIGHLOW, DVP0, DVP1. The default value is determined by the display device and the Type setting. Usually, if Type is set to External, the default value is DVP1.
Option "SerialPort" "hex number"
This option is used to set the port to sense the external transmitter/encoder. The valid values are 0x25, 0x26, 0x2C, 0x31, 0x3D. If this option is not set, the VIA driver will sense the ports following this sequence: 0x2c-> 0x31-> 0x25-> 0x3D-> 0x26.
Option "DDCPort" "hex number"
This option is used to set the port to obtain EDID. The valid values are 0x25, 0x26, 0x2C, 0x31, 0x3D. The value is usually the same as SerialPort's. Thus, this option can not be set in most cases.
Option "NoDDCValue" "boolean"
This option is used when the display device's EDID is broken, but you strongly intend to light the device. This option is not recommended to use, because the display device can be damaged. It applies to CRT and DVI.
Option "ClockPolarity" "integer"
This option is to adjust the polarity of DI port clock. Valid values are 0, 1.
Option "ClockAdjust" "integer"
This option is to adjust the value of DI port clock. The value ranges from 0 to 7.
Option "ClockDrivingSelection" "integer"
This option applies to DVP0 and DVP1. The value ranges from 0 to 3.
Option "DataDrivingSelection" "integer"
This option applies to DVP0 and DVP1. The value ranges from 0 to 3.
Option "Vt1636ClockSelST1" "integer"
This option is to adjust the DPA values of a LVDS transmitter VT1636. The value ranges from 0 to 31.
Option "Vt1636ClockSelST2" "integer"
This option is to adjust the DPA values of a LVDS transmitter VT1636. The value ranges from 0 to 15.
Option "TvEncoderDPA" "integer"
This option is to adjust the DPA values of a TV encoder VT1625. The value ranges from 0 to 15.
Option "Center"
Display in the center of the LCD panel when current mode is smaller than native mode. Without this option, LCD display is expanding.
Option "PanelSize" "size"
Manually set the LCD panel's physical size. Legal values are listed in supported list. It is used to specify the LCD panel's size when the LCD panel doesn't have its EDID or has a broken EDID. If this option
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 "MSB" "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.
Option "FixOnIGA1" "boolean"
When light dual LCD panels, set this option for one of them. There are two CRTCs in the current VIA chipsets: IGA1, IGA2. Only IGA2 has the ablility to scaling up. And LCD gets higher priority to use IGA2. So if this option is not set, LCD always uses IGA2. There would be a conflict when lighting dual LCD panels.
Option "Hotplug"
This options is used to support HDMI hot-plug function and change mode on the fly. But it will cost CPU usage.
Option "Standard" "string"
Specify the TV standard. Valid standards are "1080I", "720P", "576P", "480P", "PAL", "NTSC". If you do not set it or specify an invalid value, the default "NTSC" will be used.
Option "Signal" "string"
Specify the signal type. Valid types are "YCbCr", "RGB", "Composite", "S-Video", "Composite+S-Video", "Composite+S-Video+RGB", "Composite+S-Video+YCbCr". The default type is S-Video.
Option "Scan" "string"
Valid values are "Over", "Fit", "Normal". The default is "Normal".
Option "DedotCrawl" "boolean"
The default value is "False".
Section "Device"
Option "AccelMethod" "EXA"
Enable EXA architecture.
Option "SWCursor" "boolean"
Set the software cursor.
Option "DRI" "boolean"
This option allows to disable DRI module. The default value is true.
Section "Extensions"
Option "Composite" "boolean"
Set to use the composite extension.
Options implemented in X.org Server
Section "SeverLayout"
Option "RandR" "boolean"
Section "Monitor"
These options apply when using XRandR extension.
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"