[Bug 69128] [IVB dp dongle] Apple miniDP-to-VGA fails link training

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=69128

--- Comment #14 from Imre Deak <imre.deak at gmail.com> ---
The '[drm:intel_dp_i2c_aux_ch] *ERROR* too many retries, giving up' looks like
a VGA EDID read error.

The first dmesg had also a 'too many voltage retries, give up' error, which is
not in the latest dmesg any more, so I assume that's been fixed meanwhile.

As for the EDID issue: despite the error message the modeset seems to succeed
using a default mode; is the display on or blank for you?

Could you check if your VGA cable is DDC-2 compatible? There are cables out
there without pin 9,12,15 properly wired and with those you won't be able to
read the EDID. You can check this by using the cable on another machine and
checking with xrandr if all the modes supported by the display are listed.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20131205/04ac3aa4/attachment.html>