Created attachment 93888 [details]
tree correctly rendered

Probably the same issue than:
https://bugs.freedesktop.org/show_bug.cgi?id=74803

Trees in Left 4 Dead 2 have some rendering issue when you move, so in fact they
looks like to blink. See the screenshots attached.

This hits my RV770 (HD4850) and CYPRESS (HD5850).

When R600_DEBUG=nohyperz is set, there is no problem.
R600_DEBUG=nosb doesn't fix.

First bad commit is:
r600g: defer shader variant selection and depending state updates
commit a144bc29b5bb8322a54308603c5d0a8467448164
Signed-off-by: Vadim Girlin <vadimgirlin@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Note that the bug happens in L4D2 only when the option "Effects details" in the
graphic options of the game is set to Medium or High, but not when set to Low.