Created attachment 33226 [details] Xorg.0.log When DRI is enabled on the ATI FirePro M7740 card (Dell Precision M6400 laptop), some text and images are rendered with artifacts that I suspect are caused by texture memory issues. Increasing the FBTexPercent option to 90 causes the desktop background image to also suffer the same effect. Changing between EXA/XAA has no effect. ColorTiling on/off has no effect. Only turning off DRI will banish the artifacts.
Created attachment 33227 [details] dmesg
Created attachment 33228 [details] Screenshot (desktop 1920x1200) The GNOME screenshot produced an image which is corrupted by the same artifact in its entirety, although only some parts of the display actually contained the artifacts on-screen.
There is no XAA or tiling support for r6xx+ chips so those options don't have any affect at the moment. Does: Option "EXANoDownloadFromScreen" or Option "EXANoUploadToScreen" in the device section of your config fix the issue?
I added Option "AccelDFS" "off" to the Device section, restarted X, and now the artifacts are gone. DRI still works (glxgears -info gives "GL_RENDERER = Mesa DRI R600 (RV740 94A3) 20090101 x86/MMX/SSE2 TCL") so 3D performance is snappy, but the applications that used to show the artifacts now redraw verrrry slowly, such as Thunderbird's message list. But I can live with that. I'll attach the new Xorg.0.log for interest.
Created attachment 33233 [details] Xorg.0.log with EXA DownloadFromScreen disabled
*** This bug has been marked as a duplicate of bug 18397 ***
Fixed by Debian kernel 2.6.32-4 ("Big Bang" release) which enabled radeon KMS support (backported from 2.6.33 and 2.6.33.1).
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