The SandyBridge New Acceleration (SNA) code is intended to replace the old UXA (UMA Acceleration Architecture), but it is a large body of code and may cause problems. However, the version of the code in the version control system listed above has been tested successfully with both SNA and UXA capabilities.

To work around this problem, as well as enabling support for UXA, it is necessary to force UXA to be used by creating a configuration file. If this problem applies to you, create the following file as the root user and modify it as needed:

cat >> /etc/X11/xorg.conf.d/20-intel.conf << "EOF"
Section   "Device"
        Identifier "Intel Graphics"
        Driver     "intel"
        #Option     "DRI" "2"            # DRI3 is default
        #Option     "AccelMethod"  "sna" # default
        #Option     "AccelMethod"  "uxa" # fallback
EndSection
EOF