https://bugs.freedesktop.org/show_bug.cgi?id=30575
--- Comment #1 from Marek Olšák maraeo@gmail.com 2010-10-02 16:58:25 PDT --- Could you please try latest kernel 2.6.36-rcN? There are some hardlock fixes.
Please see also bug 29389, which describes another possible cause of hardlocks with a workaround. There is also bug 28474, where user Tormod Volden had had hardlocks with the same GPU as you and the workaround in bug 29389 helped him.
Links: https://bugs.freedesktop.org/show_bug.cgi?id=29389 https://bugs.freedesktop.org/show_bug.cgi?id=28474