For me, 4.4.0-78 actually made it worse on my Dell Latitude E7250 to the point where I had to downgrade to 4.4.0-72 in order to be able to use external monitors again.
With versions prior to 4.4.0-78, running xrandr a couple of times would usually cycle through all kinds of weird broken setups with parts of what was supposed to be shown on one monitor being shown in the corner of a different monitor and similar problems. But after a few attempts, it used to somehow "get it right" and display the right layout. With 4.4.0-78, this workaround stopped working as even though the layout may be correct, there simply is "no signal" on external monitors. They are detected by xrandr as being present and connected, the window manager appears to recognize them but neither of them receives a video signal so they just go to sleep after a few seconds. The built-in notebook display keeps working all the time. External monitors appear to work up to the point at which the switch from "VESA VGA" to "inteldrmfb" occurs. After going back to 4.4.0-72, all issues went away. Even the layout options given to xrandr now work as expected. I looks like something is horribly wrong with Intel graphics support. -- 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/1686189 Title: External monitor connecting problem on Intel graphics card To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1686189/+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
