I did a stupid thing and upgraded KDE to 4.4.3 and X.org to 7.5. Had some problems, managed to fix them, but I have one strange thing remaining. KDE says "compositing is not supported on your system". Yet it WAS supported with KDE 4.3.x and X.org 7.4. So I edit the .kwinrc file to force it on, and voila! It works!

But KDE *STILL* says it is not supported! It still says "compositing is not supported on your system" in the desktop effects dialog. But immediately below it it says also says "compositing is active". I know it works because windows are transparent, have shadows, I get switching effects, etc. All of the controls on the General and Advanced tab work, but the All effects tab is blank.

What's going on? How do I convince KDE that I really do have compositing and to provide me the complete controls for it?

System:
FreeBSD 8.0
KDE 4.4.3
X.org 7.5
radeon driver, X1650 chip
Mesa 7.6.1

Try checking "Disable functionality checks" on the Advanced tab of the Desktop Effects module.

bcooksley wrote:Try checking "Disable functionality checks" on the Advanced tab of the Desktop Effects module.

Sure I can do that. But still wondering what KDE is complaining about. Is it my aftershave? Haircut? I don't get this on my other laptop system, which DOES have compositing problems.

I tried it with "disable functionality checks", yet it still says compositing is not supported. The All Effects tab is still blank.

I had the same problem when I installed ATI Catalyst drivers and the problem was the options of xorg.conf. I removed extras options and after all works.

Maybe you need play with your xorg.conf

Interesting 'twist' on the problem. When I start kde4 as root user (using xinit, then 'startkde' (I can't log in as root through kdm.) composting is enabled. When logging in as a regular user composting is disabled. Same kernel. Same boot-up, etc... Also 'xorg.conf' by default is basically empty. It has no section or entries 'enabling' composting.