GL_ARB_shadow_ambient workaround?

[V10lator]

Hi,
I'm using a radeon HD 4670.
Now my problem is that games using GL_ARB_shadow_ambient only show grey screens. In some games I can workaround this by changing options but there are still some left. How can I workaround the issue if there are no game options disabling that extension?

[agd5f]

File a bug against the r600 gallium 3D driver and attach your xorg log, dmesg output, and glxinfo output.