Comment 110 for bug 291053

Maybe we should move hd4770 (RV740) issues to separate bug as I dont think
other chips experience the same issue. RV740 seems not to render to GTT
correctly afaik. You get a checkerboard pattern or stripes with half correct -
half garbage. The easiest way for me to reproduce is using xmag under UMS.
Just take a mag and you get a checkerboard. Using some screenshot app will also show this, just as in
http://bugs.freedesktop.org/attachment.cgi?id=33228

Under KMS I can make screen corruption (x pixmaps?) happen with some opengl game
with lots' of textures (Set to high/ultra) or also a minute or two
with googleearth. I guess it starts when kms starts to evict & bring back
buffers from vram to gtt.
I guess we'r not programming/setting up rv740 correctly.
Just to mark 2 other issues with rv740: it returns only half the occlusion query samples in ogl and pixmaps w<32 are disabbled altogether in dfs for this chip.

Andre