Arch Linux

it takes severel seconds after boot to have xrandr showing all available modes:

date; xrandr
Thu Nov 5 10:15:03 CET 2015
Screen 0: minimum 8 x 8, current 1600 x 900, maximum 32767 x 32767
eDP1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
1600x900 60.05*+
1368x768 60.00
1280x720 60.00
...
720x405 60.00
640x360 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP2-1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1440x900 59.90*+
DP2-2 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1440x900 59.90*+
DP2-3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

... and after a while (15 sec or so):

date; xrandr
Thu Nov 5 10:15:16 CET 2015
Screen 0: minimum 8 x 8, current 1600 x 900, maximum 32767 x 32767
eDP1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
1600x900 60.05*+ 40.04
1368x768 60.00
1280x720 60.00
...
720x405 60.00
640x360 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP2-1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1680x1050 59.95 +
1280x1024 75.02 60.02
1440x900 59.90*
1280x800 59.91
1152x864 75.00
1280x720 60.00
1024x768 75.08 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 60.00
720x400 70.08
DP2-2 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1680x1050 59.95 +
1280x1024 75.02 60.02
1440x900 59.90*
1280x800 59.91
1152x864 75.00
1280x720 60.00
1024x768 75.08 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 60.00
720x400 70.08
DP2-3 disconnected (normal left inverted right x axis y axis)


Please consider this reference (<http://comments.gmane.org/gmane.comp.freedesktop.xorg.cvs/31247>):

commit 627ef68a8cd7a51627d5b6a98cb0a5bdb1d9b534
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sat Oct 31 09:27:35 2015 +0000

sna: Don't extend the display mode cache for an unknown output

Here are my original postings:

- <http://unix.stackexchange.com/questions/240949/xrandr-only-lists-mode-after-a-while-of-waiting>
- <http://lists.x.org/archives/xorg/2015-December/057816.html>