Comment # 3 on bug 56918 from Tom Stellard

(In reply to comment #2)
> How do I set that?  In the GRUB kernel boot options?  Or with "setenv"?  And
> where do I look for the debugging output?  dmesg?  Xorg.log?  Or somewhere
> else?

Open a terminal a start firefox like this:

RADEON_DEBUG=fp,vp firefox &>mapsgl.log

Then do some stuff with MapsGL, close firefox and post the mapsgl.log file.