Thank you Jerome,
the suggestions helped me a little bit forward in at least elimination of one possible source of error.

I now know that the system loads the intended driver, however the error remains. glxgears works as before and gives frame rates around 600 fps, but OGRE based applications still don't work. I also checked which libraries are loaded using strace ( suggested from http://gatos.sourceforge.net/dri-debug.php ) I could also conclude that the correct library is indeed loaded.

This now leads me to believe that the error is either in the driver or in the OGRE engine.

The system uses all default binary packages from Ubuntu repositories. To build and install newest DRI drivers I assume it would also require a newer kernel (the current in system is 2.6.15-27).

Is there any other things I can try before rebuilding X and kernel?

Regards
/Michael

2006/12/30, Jerome Glisse <j.glisse@gmail.com>:
On 12/30/06, Aprak Ofatys <aprak.ofatys@gmail.com> wrote:
> I have problems with a (Ubuntu) laptop with a i915 based gfx with certain
> OpenGL applications.
>
> glxinfo rapports that DRI is enabled and programs like glxgears and ppracer
> works with good frame rates. However, when trying to run applications based
> on the OGRE framework, all I get is a black scene. Disabling DRI makes the
> same programs render the scenes.
>
>  I've carefully read a lot of problem info's and FAQ's the past days, and I
> still can't figure this out. I suspect it could somehow be related to DRI
> (either a bug or bad configuration).
>
> I haven't played around with OpenGL for some years, so DRI is completely new
> to me. I struggle to understand how everything fit's together so that I at
> least can isolate where _not_ to look.
>
> From this link (http://dri
> .freedesktop.org/wiki/DriTroubleshooting) I however I
> noticed some things that seem suspicious.
>
>
> Under "User Space setup" it says that dri drivers should be located in
> /usr/X11R6/lib/modules/dri/ , on my system these are located in
> /usr/lib/dri/ , Which would be the correct location?
> Also It says that glxinfo should output "libGL: OpenDriver: trying
> /usr/X11R6/lib/modules/dri/<name>_dri.so". This is not the
> case on my system. I've followed the hints and reinstalled libGL just to
> make sure no old or obsolete version is contaminating the system (Ubuntu
> actually seems to have an issue with this file if nvidia drivers has
> previously been installed on the system). The file belonged to the package
> libgl1-mesa, but reinstalling it did not make any difference.
> Neither 'export LIBGL_DEBUG=verbose' nor setting any other environment
> variables seems to make any difference. Unless I'm missing something
> obvious, setting this variable in a shell from where a OpenGL program is
> run, should mean outputting some debug info on the stdout/stderr?
> The system-wide configuration file /etc/drirc (mentioned in
> http://dri.freedesktop.org/wiki/ConfigurationInfrastructure)
> does not exist.
>
> I can't figure out which part of the system is responsible for loading
> /usr/lib/dri/i915_dri.so. Running 'ldd /usr/lib/libGL.so' doesn't seem to
> imply any dependency on any DRI libraries.
>
> Any hint's about how to debug the various layers involved would be most
> welcome.  Is it possible to profile libGL .so in any way so that calls to
> each function results in output in some file in case there actually exists a
> bug and I need to isolate exactly where?
>
> Any advice is welcome.
>
>  Regards
> /Michael

Try by setting LD_PRELOAD=/usr/lib/libGL.so then launch ogre some engine
use dlopen with LAZY flags (or the other don't remember) and thus fail to
properly figure out DRI, i think you are experiencing somethings along thus
line with ogre.

Don't worry for the path /usr/X11R6 is old path of non modular xorg, since
then (since xorg modular which i think is in use in your ubuntu distro) lib and
module are under /usr/lib.

best,
Jerome Glisse