Not sure what happens when you do make install in shared-core. I was running make and make install at the top level to update libdrm and headers, then another make in linux-core to produce the actual drm binary files. I didn't think building in shared-core actually did anything -- AFAIK the shared-core files are only used when you build linux-core or bsd-core
Looks like the instructions at http://www.x.org/wiki/radeonhd%3Aexperimental_3D call for two separate invocations of make + make install, one for libdrm and one for shared-core. Not sure if that is any better than one invocation at the top level.
shared-core is where the files that are shared between linux and bsd live. There's nothing to build in there. The files are symlinked into linux-core and bsd-core. The kernel modules for linux are built in linux-core.
just wanted to say that I have the same problem like Nille. Using a integrated Radeon HD3200 here (RS780 chipset).
Did check it with a fresh mesa git checkout (r6xx-rewrite branch) and the corresponding DRM module from Alex's repo. libdrm is git master with the radeon API enabled. xf86-video-ati is also git master, another recent compile.
Loading the DRM module works without problems, starting X works flawlessly but starting glxgears just "blacks" the current desktop.
Nothing suspicious in the kernel log, haven't checked Xorg.log though. And it's not like the app, driver or kernel crashes or anything. It's just that the screen turns black.
I can switch back and forth between X and the console, and also between my 4 virtual desktops (using XFCE). The only desktop that stays black is the one where glxgears was called. I can kill it from another desktop, then switch back, having some mild screen corruption which reverts back to normal once I open some apps or resize windows.
So it's definitely better than before where calling glxgears crashed the whole X server.
I read that glxgears is supposed to work now, so are we encouraged to open bug reports for such problems, or is it still too early for something like that?
I can generate logs, backtraces and stuff, if that helps. Just let me know what you need.
EDIT: It just came to my mind that I have the XFCE compositor enabled, I'll check if this is a problem later.