The same problem (external interface DP1 showing as disconnected, sometimes showing the resolutions) happens to me on my Macbook Air 4,2 since already Ubuntu 12.10. This affects also derivatives like Mint and also other distributions like Archlinux. From this I would conclude that it is a general problem with the kernel and/or Intel Xorg driver.
The problems depend a little bit on the external monitor that I am using: A normal 19'' LCD with VGA connector works sometimes (after rebooting, suspend/resume, disconnecting/reconnecting). A no-name LCD TV (also VGA connector) doesn't work even with trying all of the things that worked for the 19''. The problems seemed to be gotten worse with Ubuntu 13.04 in comparison with 12.10. With 12.10 I could also get the TV to work after playing around a little bit. As I am using the Air to give talks, this is a major deal-breaker (as also projectors don't work anymore) and the only reason why I still have to boot Mac OS X (there everything works fine). If i can help with logs or testing something, feel free to tell me. Another thing: What I can do is force the monitor to some resolution. As Michael mentioned, the monitor is then switched on, but as xrandr still shows the monitor as disconnected, one can't really use it. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1165965 Title: External display stopped working on MacBook Air Status in “linux” package in Ubuntu: Confirmed Bug description: After upgrading to 13.04 beta, my external monitor is no longer detected/driven. This works perfectly under 12.10, and is therefore a major regression impacting common use cases. When the Display Port/VGA adapter is plugged in dmesg reports 15 instances of: [drm:intel_dp_i2c_aux_ch] *ERROR* too many retries, giving up Hardware: MacBook Air 2012 Display configuration: Apple Display Port to VGA adaptor Ubuntu version: 13.04 beta. --- ApportVersion: 2.9.2-0ubuntu5 Architecture: amd64 DistroRelease: Ubuntu 13.04 EcryptfsInUse: Yes InstallationDate: Installed on 2012-07-24 (258 days ago) InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425) MarkForUpload: True Package: linux (not installed) Tags: raring Uname: Linux 3.9.0-030900rc6-generic x86_64 UnreportableReason: The running kernel is not an Ubuntu kernel UpgradeStatus: Upgraded to raring on 2013-04-07 (2 days ago) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1165965/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
