[Bug 56834] [ivb DP dual link DVI dongle regression] [drm:intel_dp_i2c_aux_ch] *ERROR* too many retries, giving up

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=56834

--- Comment #39 from freeseek <giulio.genovese at gmail.com> ---
I have the same problem with a Lenovo X220 and a BizLink diplay port adapter,
as I upgraded to Ubuntu 14.04. I am currently using 3.15.0-031500rc5-generic.
As per comment #36 I also need to add the correct external monitor display with
xrandr. I then use the following command to switch from the laptop screen to
the monitor screen: "xrandr --output LVDS1 --off --output VGA1 --off --output
HDMI1 --off --output DP1 --mode 2560x1600".

Every other time this will fail, and it looks like the laptop tried to switch
to DP1 unsuccessfully and then reverted to LVDS1. Occasionally, this will also
crash the machine requiring a hard reset. Once the laptop finally succeeds in
using DP1, running a program like xrandr or unity-control-center will
immediately trigger something and revert the display to LVDS1 (100%
reproducibility), possibly crashing the system. Each time the laptop reverts to
LVDS1 it triggers a message like the one in Comment #33 in dmesg.

I will also add that "get-edid" completely fails and shows no useful output. It
says something like "Looks like no busses have an EDID. Sorry!" and "The EDID
data should not be trusted as the VBE call failed". The same Bizlink adapter
works flawlessly on a Mac.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20140517/c96568d8/attachment.html>