https://bugs.freedesktop.org/show_bug.cgi?id=30152
--- Comment #8 from Marek Olšák maraeo@gmail.com 2010-09-27 18:34:47 PDT --- Actually, all vertex shader outputs are sent to the rasterizer in r300g and therefore they occupy texcoord slots. We cannot disable unused outputs via some hardware state, but I guess we could recompile the vertex shader based on what inputs are read by the fragment shader.