This bug occurs even when just playing a video with VLC. It seems to occur only when multiple displays are attached and only in some configurations. In particular non-clone configurations seem to be affected. The workaround that helped me was
Option "AccelMethod" "uxa" in the "Device" section of xorg.conf. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1243261 Title: apparent GPU hang on haswell laptop when playing movie on libreoffice To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1243261/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp