Radeon 9200 + glxinfo = 100% CPU for hours

[dirk_salewski]

Hello NG,

I have a weird problem with my Radeon 9200 and didn't find the solution so far, so if anyone had the same problem I'd be eager to hear about the fix.

The Environment:
- AMD64, profile 2005.1
- xorg-x11-6.8.2-r1
- Kernel gentoo-sources-2.6.9-r14
- xfce4
- root-tail

1) If I don't enable the composite extension in my xorg.conf, almost everything is o.k. - i can run glxinfo and get immediate results, glxgears gives about 2050 FPS (apart from bzflag no games here), rendering isn't too sluggish, fine. Except for a display problem with root-tail - if I move a window, the root-tail-output remains invisible to me (I see only the background picture then).

2) Now I enable the composite extension. Nice, interesting effects, transparency, rendering just a tiny bit more sluggish, root-tail working like a charm - but if I issue "glxinfo" it hangs for a short moment after the first line, the outputs the rest as expected. In this moment CPU usage jumps to 100% and stays there for hours (which is quite annoying if You want to work with the machine). If i issue "glxgears" CPU-usage drops to 5-20%, but only as long as glxgears is kept running. After closing the gears, CPU jumps up to 100% again. If I wait hours and hours, CPU falls back to normal. Strange, isn't it?


What did I do to solve the problem:

1) Tested xorg-x11-6.8.2-r2: Not good, since it didn't fix the problem and made program icons run amok.
2) Tested other kernels: Not good, since hsfmodem (my fax depends on this) doesn't compile with other kernels (?!). Being not able to fax is worse than not seeing my logs.
3) Tried not to run glxinfo: Didn't help - there must be other programs triggering this bug. Probably xscreensaver.
4) Made sure that it has nothing to do with standard xorg.conf options (like "Load dri" or something).
5) Read the documentation - learned that composite is considered unstable. Filed a bug with xorg. No response so far.
6) Tried ati-drivers: Not good - performance worse than open source drivers, and composite not supported at all. Switching to VTs impossible - those ati-guys definitely have to work on these drivers.
7) Basic voodoo in xorg.conf: Section "Device", Option "backingstore" "1" - had absolutely no effect.


I think that there is a problem with opengl and composite here - but neither Xorg.0.log nor dmesg tell me about it. My Question - is it possible to selectively disable OpenGL Features? How? Maybe I could switch off one OpenGL-Feature at a time and wait until I find a working setup. Or does anybody have a better idea.

Greetings,

Dirk