https://bugs.freedesktop.org/show_bug.cgi?id=28800
--- Comment #2 from Chris Rankin rankincj@googlemail.com 2010-07-06 12:33:59 PDT --- I tried running WoW with the RADEON_DEBUG="tex" option, and noticed that many textures were in formats:
dxt1_rgba dxt3_rgba dxt5_rgba
And so because I am also using libtxc_dxtn070518.tar.gz, I moved the libtxc_dxtn.so object out of /usr/lib and tried running WoW again. And this time, the textures were all fine... right up until WoW crashed a few seconds later.
From this I conclude that:
a) Both r300c and r300g have difficulty with compressed textures, and b) r300g also has a more serious problem with b8g8r8a8_unorm, b4g4r4a4_unorm, b5g6r5_unorm textures (and possibly others), because these are what WoW uses when compressed texture support isn't available.