So, I was checking out the latest OSS drivers for my R670 chipset and installed everything (radeon,mesa,dri,drm,gl) from GIT on my Arch 2.6.32 x64 stock kernel.
Everything was nice (thank you devs ^^) until I saw a weird bug; the GPU will hang when the computer goes idle.
And by idle I mean the setting on the screensaver config dialog, if I put the slide on 1 minute it will hang in a minute of being idle, if I put it 5 minutes it will hang 5 minutes of being idle even if I don't tick the "activate screensaver" box. Previewing the screensaver works OK too.
I also notice that only the GPU is actually hanged as I was watching a clip and the sound kept going when the picture (and mouse cursor) froze.