https://bugs.freedesktop.org/show_bug.cgi?id=40935
--- Comment #7 from Jerome Glisse glisse@freedesktop.org 2012-06-18 07:38:21 PDT --- All my r300 works fine with KMS (and i have a lot of them), you just an unlucky user. Not all r300 are affected, it's most likely the combination of your gpu with your motherboard.