I've created a preliminary patch that fixes gtt related cache coherency problems at least for my i855GM. Look here for instructions:
http://bugs.freedesktop.org/show_bug.cgi?id=26345#c61
I've created a preliminary patch that fixes gtt related cache coherency problems at least for my i855GM. Look here for instructions:
http:// bugs.freedeskto p.org/show_ bug.cgi? id=26345# c61