Sorry I didn't see this thread earlier, but if you don't use the xorg.conf option and instead use libgl1-mesa-dri-gallium's r300_dri.so (which is a renamed radeong_dri.so) then X will load the classic mesa driver (/usr/lib/dri/r300_dri.so) because it's hardcoded to look for r300_dri.so in /usr/lib/dri and the gallium package is using a --with-dri-searchpath hack pointing at /usr/lib/dri-gallium. Indirect will use classic mesa instead of the gallium one and you'll notice you have a large amount less GLX Visuals and GLXFBConfigs available in glxinfo even when direct, and GLX over SSH will just segfault. People were reporting compiz problems to me using the /usr/lib/dri-gallium setup as well which were fixed by using the gallium stuff directly in /usr/lib/dri. Making gallium the default driver will break UMS. I added the xorg.conf option as a tradeoff to work around both of those problems.
No announcement yet.
Radeon Gallium on ubuntu