Created attachment 116318 [details]
Screenshot of bug

Hi,

I'm trying to run the game The Witcher (in Wine) it has rendering errors when
drawing the rain.

This bug is present in both git master
(78395dbf9ff429d98523f8b4a340f7188d8b4db0) and in 10.5.5.

I made an apitrace of the game and it renders without problem on i965. 

Running the trace on r600 results in this warning:

101172: glDebugOutputCallback: Medium severity API unknown issue 1, FBO
incomplete: driver marked FBO as incomplete [-1]

This is on a Redwood, Radeon HD 5670 1GB.