7. General Trouble Shooting

This section contains information to help you diagnose general problems. See below for additional information for specific hardware.

7.1. Starting the X server

1. Before you start the X server, verify the appropriate 3D kernel module is installed. Type lsmod and look for the appropriate kernel module. For 3dfx hardware you should see tdfx, for example.
2. Verify you're running XFree86 4.0 and not an older version. If you run xdpyinfo and look for the following line near the top:

               vendor release number:    4000
           
   

3. Verify that your XF86Config file (usually found at /etc/X11/XF86Config) loads the glx and dri modules and has a DRI section.

   See the Software Resources section below for sample XF86Config files.

4. Examine the messages printed during X server startup and check that the DRM module loaded. Using the Voodoo3 as an example:

           (==) TDFX(0): Write-combining range (0xf0000000,0x2000000)
           (II) TDFX(0): Textures Memory 7.93 MB
           (0): [drm] created "tdfx" driver at busid "PCI:1:0:0"
           (0): [drm] added 4096 byte SAREA at 0xc65dd000
           (0): [drm] mapped SAREA 0xc65dd000 to 0x40013000
           (0): [drm] framebuffer handle = 0xf0000000
           (0): [drm] added 1 reserved context for kernel
           (II) TDFX(0): [drm] Registers = 0xfc000000
           (II) TDFX(0): visual configs initialized
           (II) TDFX(0): Using XFree86 Acceleration Architecture (XAA)
                   Screen to screen bit blits
                   Solid filled rectangles
                   8x8 mono pattern filled rectangles
                   Indirect CPU to Screen color expansion
                   Solid Lines
                   Dashed Lines
                   Offscreen Pixmaps
                   Driver provided NonTEGlyphRenderer replacement
                   Setting up tile and stipple cache:
                           10 128x128 slots
           (==) TDFX(0): Backing store disabled
           (==) TDFX(0): Silken mouse enabled
           (0): X context handle = 0x00000001
           (0): [drm] installed DRM signal handler
           (0): [DRI] installation complete
           (II) TDFX(0): direct rendering enabled
           
   

5. After the X server has started, verify that the required X server extensions are loaded. Run xdpyinfo and look for the following entries in the extensions list:

   	  GLX
   	  SGI-GLX
   	  XFree86-DRI
           
   

7.2. Linking, running and verifying 3D acceleration

After you've verified that the X server and DRI have started correctly it's time to verify that the GL library and hardware drivers are working correctly.

1. Verify that you're using the correct libGL.so library with ldd. The /usr/lib and /usr/X11R6/lib directories are expected locations for libGL.so.

   Example:

           % ldd /usr/local/bin/glxinfo
                   libglut.so.3 => /usr/local/lib/libglut.so.3 (0x40019000)
                   libGLU.so.1 => /usr/local/lib/libGLU.so.1 (0x40051000)
                   libGL.so.1 => /usr/lib/libGL.so.1 (0x40076000)
                   libXmu.so.6 => /usr/X11R6/lib/libXmu.so.6 (0x402ee000)
                   libXi.so.6 => /usr/X11R6/lib/libXi.so.6 (0x40301000)
                   libm.so.6 => /lib/libm.so.6 (0x40309000)
                   libc.so.6 => /lib/libc.so.6 (0x40325000)
                   libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x40419000)
                   libXt.so.6 => /usr/X11R6/lib/libXt.so.6 (0x404bd000)
                   libSM.so.6 => /usr/X11R6/lib/libSM.so.6 (0x40509000)
                   libICE.so.6 => /usr/X11R6/lib/libICE.so.6 (0x40512000)
                   libXext.so.6 => /usr/X11R6/lib/libXext.so.6 (0x40529000)
                   libvga.so.1 => /usr/lib/libvga.so.1 (0x40537000)
                   libpthread.so.0 => /lib/libpthread.so.0 (0x4057d000)
                   /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
           
   

2. You may also double check that libGL.so is in fact DRI-capable. Run strings libGL.so.1.2 | grep DRI and look for symbols prefixed with "XF86DRI", such as "XF86DRIQueryExtension".
3. To be safe one should run ldconfig after installing libGL.so to be sure the runtime loader will find the proper library.
4. Verify that the appropriate 3D driver is in /usr/X11R6/lib/modules/dri/ For example, the 3dfx driver will be named tdfx_dri.so.
5. Set the LIBGL_DEBUG environment variable. This will cause libGL.so to print an error message if it fails to load a DRI driver. Any error message printed should be self-explanatory.
6. Run glxinfo. Note the line labeled "OpenGL renderer string". It should have a value which starts with "Mesa DRI" followed by the name of your hardware.
7. Older Linux OpenGL applications may have been linked against Mesa's GL library and will not automatically use libGL.so. In some cases, making symbolic links from the Mesa GL library to libGL.so.1 will solve the problem:

           ln -s libGL.so.1 libMesaGL.so.3
           
   

   In other cases, the application will have to be relinked against the new XFree86 libGL.so.

   It is reported that part of the problem is that running ldconfig will silently rewrite symbolic links based on the SONAME field in libraries.

If you're still having trouble, look in the next section for information specific to your graphics card.