Created attachment 121741 [details]
artifacts/corruption in atom editor

Hello -

I have several major glitches using intel video. Two of these may be quite separate:

One is regarding artifacts on the screen and rendering -- for example with "TearFree" "false", the terminal shows artifacts from previous states and becomes nearly unusable - on the other hand setting "TearFree" "true" seems to create another issue where the screen will (very briefly flicker black between frequent refreshes, e.g. when scrolling or tailing a large amount of text).

The other is excessive corruption (I've seen it in other programs but far less frequently for whatever reason) and rendering problems when using Chrome or other chrome based applications (atom-editor). Even with "TearFree" "true" I still experience corruption in atom-editor lines, switching between files sometimes causes the screen to the write the text buffer one by one scanning down etc.

I have experimented with a number of parameters, none of which seem to help much (setting "AccelMethod" to "uxa" makes the desktop very very slow but doesn't seem to fix much, I've tried glamor as well).
These issues appear to persist across both GL and non-GL based composite managers (tested with gnome-desktop and openbox+xcompmgr).

uname -a 
Linux d-pc 4.4.0-4-ARCH #1 SMP PREEMPT Wed Jan 20 07:42:27 CET 2016 x86_64 GNU/Linux

lspci | grep VGA                                                                             
00:02.0 VGA compatible controller: Intel Corporation Device 191b (rev 06)

/etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   Option      "TearFree" "true"
   # Option      "AccelMethod"  "sna"
   # Experimental Accelmethod
   Option      "AccelMethod"  "glamor"
   # "DRI"	"2" is default
   Option      "DRI"    "3"
   BusID       "PCI:0:2:0"
EndSection

pacman -Q | grep intel
xf86-video-intel 1:2.99.917+519+g8229390-1