This behaviour is still present with kernel 4.2.0-7-generic - when an external display is connected the desktop becomes incorrect tiled/scaled, and the displays rapidly (~10 Hz) flicker.
Having the external display (Apple Cinema 27) plugged in during boot is no longer a reliable workaround. Usually it displays a correct login screen at native resolution, then the flickering begins when a desktop session starts. I've found a better workaround, pressing Super+S triggers 'spread mode' causes each display to show a zoomed out overview of the entire desktop. This (so far) reliably fixes the flickering and the tiling. Perhaps I've filed this under the wrong package, could it be a bug in Mir or Unity? -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1488409 Title: [MacbookPro11,2] Using external displays show corrupted, flickering images To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1488409/+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