https://bugs.freedesktop.org/show_bug.cgi?id=28771
--- Comment #24 from Sven Arvidsson sa@whiz.se 2010-08-18 13:22:16 PDT --- I compared how Intel (i965) compares when it comes to DRI2 and vsync, and as far as I can tell they have the same problems (needs a special driver="dri2" stansa in drirc, toggling vsync inside a game doesn't work).
This bug can proabably be closed as resolved for radeon, and bugs for the shortcomings mentioned above filed against DRI2.