I'm not shure but few minutes ago I saw into
xorg.conf or XF86Config files, about DRI
as follow:
Section "Module"
Load "dbe" # Double-Buffering Extension
Load "v4l" # Video for Linux
Load "extmod"
Load "type1"
Load "freetype"
Load "synaptics"
Load "/usr/X11R6/lib/modules/extensions/libglx.a"
Load "glx" # 3D layer
Load "dri" # direct rendering
EndSection
Shure..../etc/X11 directory
Do I hope be useful...