But it works when I start X manually before stopping them again and running gdm. It's explained at: https://bugs.gentoo.org/show_bug.cgi?id=403283#c39 In my case, it's caused by this: https://bugs.freedesktop.org/show_bug.cgi?id=62141 And this patch fixes the problem: http://git.chromium.org/gitweb/?p=chromiumos/overlays/chromiumos-overlay.git;a=blob;f=media-libs/mesa/files/9.0-i965-Make-sure-we-do-render-bet%20ween-two-hiz-flushes.patch;h=590b13b4c3da13be6ad8a8115576e6320cef7825;hb=HEAD Thanks for applying it Reproducible: Always
Looks like upstream is still undecided about this patch. A workaround is to disable rc6 using i915.i915_enable_rc6=0 kernel parameter.
looks like this was the final commit as I can read in upstream report: http://cgit.freedesktop.org/mesa/mesa/commit/?h=9.1&id=1dfea559c3
Fixed in mesa-9.1.3