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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - Kernel 4.7.x does nor initialize external DisplayPort in Dell E7250 making it unusable"
href="https://bugs.freedesktop.org/show_bug.cgi?id=97397#c4">Comment # 4</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - Kernel 4.7.x does nor initialize external DisplayPort in Dell E7250 making it unusable"
href="https://bugs.freedesktop.org/show_bug.cgi?id=97397">bug 97397</a>
from <span class="vcard"><a class="email" href="mailto:loirotte@gmail.com" title="Philippe Dosch <loirotte@gmail.com>"> <span class="fn">Philippe Dosch</span></a>
</span></b>
<pre>Hi,
It seems that I meet the same bug after having upgraded from ubuntu
16.04 to ubuntu 16.10. I'm now with a 4.8.0 kernel. Since the upgrade,
I'm unable to connect a video projector on my VGA port (whereas it has
perfectly worked with the two former releases). Strangely, if I
connect an external monitor with the same resolution than my laptop
(1920x1080), the monitor is detected and works. After having met
Lukasz on the Xorg ML, I've tried to boot on a 4.6.3 kernel and I'm
now able to make the video projector works.
Details on my configuration
===========================
Laptop HP EliteBook 840 with a i915 graphics card using kubuntu 16.10,
and a video projector connected to the VGA port.
1) Kernel 4.8.0
------------
phil@IUTNC-DOSCH i915 % uname -a
Linux IUTNC-DOSCH 4.8.0-26-generic #28-Ubuntu SMP Tue Oct 18 14:39:52 UTC 2016
x86_64 x86_64 x86_64 GNU/Linux
When I boot, the message "[drm:intel_dp_start_link_train [i915]]
*ERROR* failed to update link training" appears 3 times in dmesg.
phil@IUTNC-DOSCH i915 % xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y
axis) 309mm x 173mm
1920x1080 60.05*+ 59.93
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1280x1024 60.02
1440x900 59.89
1280x960 60.00
1360x768 59.80 59.96
1152x864 60.00
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
960x600 60.00
960x540 59.99
800x600 60.00 60.32 56.25
840x525 60.01 59.88
800x512 60.17
700x525 59.98
640x512 60.02
720x450 59.89
640x480 60.00 59.94
680x384 59.80 59.96
576x432 60.06
512x384 60.00
400x300 60.32 56.34
320x240 60.05
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
2) Kernel 4.6.3
------------
phil@IUTNC-DOSCH ~ % uname -a
Linux IUTNC-DOSCH 4.6.3-040603-generic #201606241434 SMP Fri Jun 24 18:36:33
UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
When I boot, there is none message as the one above (so no more error
message about the i915 card). Even if the video projector is
physically connected to the VGA port, it seems it is logically seen as
a DP one:
phil@IUTNC-DOSCH testkern % xrandr
Screen 0: minimum 320 x 200, current 1920 x 1848, maximum 8192 x 8192
eDP-1 connected primary 1920x1080+0+768 (normal left inverted right x axis y
axis) 309mm x 173mm
1920x1080 60.05*+ 59.93
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1280x1024 60.02
1440x900 59.89
1280x960 60.00
1360x768 59.80 59.96
1152x864 60.00
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
960x600 60.00
960x540 59.99
800x600 60.00 60.32 56.25
840x525 60.01 59.88
800x512 60.17
700x525 59.98
640x512 60.02
720x450 59.89
640x480 60.00 59.94
680x384 59.80 59.96
576x432 60.06
512x384 60.00
400x300 60.32 56.34
320x240 60.05
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected 1024x768+424+0 (normal left inverted right x axis y axis) 0mm x
0mm
1024x768 60.00*
800x600 60.32 56.25
848x480 60.00
640x480 59.94
HDMI-2 disconnected (normal left inverted right x axis y axis)</pre>
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