glx and xfree86 not working: why?

[Anthony Campbell <ac@acampbell.org.uk>]

I am using xserver-xfree86 4.2.1-6 with a Matrox G550 card.

Eveything works provided I don't enable the glx module in
/etc/X11/XF86-Config-4.

Two questions:

    1. What exactly does this module do?

    2. If it is important, is there any way to enable it?

Product of glxinfo:

    ac:~:$ glxinfo
name of display: :0.0
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Error: couldn't find RGB GLX visual

   visual  x  bf lv rg d st colorbuffer ax dp st accumbuffer  ms  cav
 id dep cl sp sz l  ci b ro  r  g  b  a bf th cl  r  g  b  a ns b eat
----------------------------------------------------------------------
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
0x21 24 tc  0  0  0 c  .  .  0  0  0  0  0  0  0  0  0  0  0  0 0 None
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
0x22 24 dc  0  0  0 c  .  .  0  0  0  0  0  0  0  0  0  0  0  0 0 None


AC
    

-- 
ac@acampbell.org.uk    ||  http://www.acampbell.org.uk
using Linux GNU/Debian ||  for book reviews, electronic 
Windows-free zone      ||  books and skeptical articles