kernel-packages team mailing list archive

[Hans-Peter Schadler <1165965@xxxxxxxxxxxxxxxxxx>]

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

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