https://bugs.freedesktop.org/show_bug.cgi?id=86720
--- Comment #27 from Benjamin Bellec b.bellec@gmail.com --- (In reply to noga.dany from comment #26)
I tried run it with nosb parameters like mentioned above "R600_DEBUG=nosb force_s3tc_enable=true /usr/bin/steam %U" and game works, but textures looks very bad.
Remove the "force_s3tc_enable=true" in your command.
And be sure to have the s3tc lib installed (libtxc_dxtn). You can check that with this command: $ glxinfo |grep s3tc