https://bugs.freedesktop.org/show_bug.cgi?id=33172
--- Comment #2 from Tobias Jakobi liquid.acid@gmx.net 2011-01-19 14:35:02 PST --- We (Jan and me) did some tests today and found out that the issue is probably related to the use of VBOs (or more specifically: not using them).
In ut2004 there is a option called 'UseVBO' for the OpenGL renderer. I guess enabling this one lets the engine use the 'ARB_vertex_buffer_object' extension. It turned out that in my ut2004 config it was enabled, but Jan had it disabled. So after enabling it for Jan the rendering suddenly worked. And when I disabled UseVBO on my system it suddenly failed and produced the black screen, plus the relocation parser errors in the kernel log.
I can only guess here, but maybe the problem is with Gallium's immediate mode implementation -- if that's how the engine submits vertices when ARB_vbo is not used.
The next thing we found out is even more interesting: In ut2003 there is no such option, so he had to stick to the 'immediate mode' rendering path. All the tests were done on Jan's system. We noticed that is was possible to get ingame when being logged in as root. This only worked for a short time, maybe like 10 seconds, before the game segfaulted. After it segfaulted, it wasn't possible any more to get ingame. The game just instantly segfaulted. Restarting X didn't help, only a full reboot did the trick.
Another thing that worked: Reboot, start ut03 as root, watch some game scenary for like 3 seconds, quickly exit the game, start ut03 as root, repear procedure...
The maximum amount of time we managed to get into game was three. After that it didn't work any more.
It was like we hit some memory leak, maybe in VRAM?
Then we switched over to ut2004 and disabled UseVBO there. We got the black screen (with the kernel messages) when we got ingame and then we waited a bit. But just like ut03 the game segfaulted after some seconds and we even managed it at one time to trigger the kernel OOM killer.