https://bugs.freedesktop.org/show_bug.cgi?id=105426

--- Comment #3 from iive@yahoo.com --- Created attachment 137961 --> https://bugs.freedesktop.org/attachment.cgi?id=137961&action=edit terminal log of "MESA_GLSL=dump R600_DEBUG=nosb,vs,ps wine steam.exe"

I'm attaching full log created with "MESA_GLSL=dump R600_DEBUG=nosb,vs,ps wine steam.exe &> glsl_error.log"

The most relevant line in the output seems to be this one:

"error: declarations for shader output `gl_BackSecondaryColor` are in gl_PerVertex and gl_PerVertex"

It looks like the bug is not related to the R600 driver, but to the glsl-compiler.