Think this bug may also be affecting me on a second-gen Dell Sputnik (XPS13). Accidentally upgraded to 13.04, and DisplayPort support seems totally broken. Both gnome-control-center and xrandr claim DP1 is unconnected.
$ xrandr Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 32767 x 32767 eDP1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 294mm x 165mm 1920x1080 60.0*+ 59.9 40.0 1680x1050 60.0 59.9 1600x1024 60.2 1400x1050 60.0 1280x1024 60.0 1440x900 59.9 1280x960 60.0 1360x768 59.8 60.0 1152x864 60.0 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 VGA1 disconnected (normal left inverted right x axis y axis) HDMI1 disconnected (normal left inverted right x axis y axis) DP1 disconnected (normal left inverted right x axis y axis) $ sudo lspci -v | grep -C 12 Graphics 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller]) Subsystem: Dell Device 058b Flags: bus master, fast devsel, latency 0, IRQ 42 Memory at d0000000 (64-bit, non-prefetchable) [size=4M] Memory at c0000000 (64-bit, prefetchable) [size=256M] I/O ports at 2000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [a4] PCI Advanced Features Kernel driver in use: i915 -- 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 : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp