Created attachment 91419 [details] Xorg.0.log - Chipset: HM65 - System architecture: x86-64 - xf86-video-intel version: 2.21.15 - xserver version: 1.14.5 - mesa version: 9.2.2 - libdrm version: 2.4.50 - kernel version: 3.11-2-amd64 - linux distribution: Debian (testing) - machine: HP Folio 13 - 2000 - display connector: HDMI Most of the time (~70%) I get rendering issues in gnome-shell immediately after logging in (see attached video). It makes no difference if I have my external display connected or not. Normally logging out and back in (one or two times) solves the problem. After logging in I change into gnome-shell activities view. If I see rendering issues I log out and in again until I get a normal view – then the problem is solved for the whole session (the problem won't occur after some time).
Created attachment 91420 [details] dmesg output with boot option "drm.debug=0x06"
Created attachment 91421 [details] video showing rendering issues
Sorry, I forgot to mention that this is a regression, I didn't have this problem in Debian stable. I'm not sure but as far as I remember I first encountered these rendering issues right after gnome 3.8 arrived in Debian testing.
The described visual artifacts seem to be caused by a bug in gnome-shell, see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=743810
Since this bug was confirmed on many different systems it seems proven to me that this is no hardware specific bug but a gnome-shell bug. So I'm closing this bug.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.