Part VII. Known Issues

The issues listed as following still exist in this release and are in the process of being resolved.

Known Issues

I. Not using XRandR extension

HDMI support

Interlaced modes are supported on VX855/VX875 chipsets, but have some issues.

Two CRTs support

Two CRTs support is for customized products. It doesn't apply to normal cases.

Display combination of LCD and DVI

The display combination of LCD and DVI is not supported on CN700.

3D application support

It has some issues to support Quake 3 when depth is 16.

II. Using XRandR extension

HDMI support

Interlaced modes are supported on VX855/VX875 chipsets, but have some issues. It may not light when X starts, but need to be triggered by command line.

Scaling

Not support.

Display device setting under console and X

The display device which is enabled under console mode but disabled in graphics mode, can not be enabled when switch graphics mode to console.

3D application support

Tuxracer is not working.

 

Issues that will not be fixed

Display combination

VX855/VX875 supports internel single-channel LVDS, but doesn't support internal dual-channel LVDS, internal TMDS, or internal TV encoder.

Clone mode and mode setting

When using XRandR extension, it's recommended to set the same mode for two display devices. That is because the display content is from the same buffer, but the menu bar will fit the primary screen's resolution, if the secondary screen's mode is different, the menu bar's position will not fit the screen size or be invisible. The same mode setting also benefits video playback with full screen.

XV overlay and XV texture video

When playback one xv texture video with one xv overlay, and xv texture video overlaps the xv overlay, xv texture video may have garbage. It also happens to x11 + xv overlay/vmf.

XVideo flicker when resize or move

You might have this issue when play the XVideo with mplayer. It could be solved by adding the parameter: -vo xv:ck-method=bg

3D desktop effects

The GL_ARB_fragement_program extension is not supported, so the water effect could not be applied.

XVideo and 3D desktop effects

XVideo hardware overlay can not enjoy the 3D desktop effects, while Xv texture video supports 3D rendering.

3D DRI and 3D desktop effects

3D DRI can not enjoy the 3D desktop effects.

Compiz and depth setting

To enable 3D desktop with compiz, the default depth should be set to 24bpp/32bpp. Otherwise, 2D APs' window will be abnormal, and can not move.

Hardware rotation

Hardware rotation is not supported on CN700.

Hardware cursor and clone mode

Hardware cursor has some issues on CN700, because CN700 has only one hardware icon. Sometimes cursor will jump between two screens when moving it. And if one screen rotates but another doesn't, the cursor icon will not rotate on the rotated screen.

Rotation configuration

If set the rotation in xorg.conf, and do it again by command line, X will crash. For example, set rotate "inverted" for DVI in xorg.conf, and excute command: xrandr --output DVI --reflect xy, X will crash.

I. Not using XRandR extension

User specified modeline

The user specified mode could not be larger than the largest mode reported by the display device's EDID. If you insist to light that mode, add the option "NoDDCValue" in the Section Device. But it's not recommended.

Combination of Two LCD panels

To light the combination of two LCD panels, two panels should have the same size.

3D DRI/Desktop and SAMM mode

Xinerama will disable DRI under SAMM mode. Thus 3D DRI is not supported, and 3D Desktop effect could not be enabled under SAMM mode.

3D desktop effect and hardware rotation

3D desktop effect is not supported when hardware rotation is enabled.