Notebook: HP EliteBook 840 G1 (Core i7-4600U, HD Graphics 4000) Docking station: HP UltraSlim Dock 2013 Monitors: 2x Dell U2414H (1920x1080, DisplayPort) Software: Linux 3.15.1, X.Org 1.15.99.903, xf86-video-intel 2.99.912 The docking station has two DisplayPort connectors. Both are connected to an external Dell U2414H monitor. But GNOME and xrandr only see DP1 but not DP2. (And for some reason the first external monitor is mirrored on the second external monitor.) # xrandr Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767 eDP1 connected (normal left inverted right x axis y axis) [...] DP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 527mm x 296mm [...] HDMI1 disconnected (normal left inverted right x axis y axis) DP2 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)
Created attachment 101300 [details] xrandr --verbose
Created attachment 101301 [details] dmesg
Please boot with drm.debug=0xe, reproduce the issue and then attach dmesg for everything. Also, is this a regression?
Created attachment 101302 [details] X.Org log
Created attachment 101303 [details] Linux kernel config
Created attachment 101305 [details] dmesg drm.debug=0xe Thank you for the quick reply. I've booted with drm.debug=0xe and attached the dmesg output. I've never used external monitors before and therefore at the moment cannot say whether this is a regression or not. Would it help if I tried to reproduce this problem with a) old Linux Kernel b) old X.Org or c) old xf86-video-intel? (Btw, both external displays are independently recognized in Windows 7. So this is not a hardware issue.)
(In reply to comment #0) > Notebook: HP EliteBook 840 G1 (Core i7-4600U, HD Graphics 4000) Just noticed a typo. Must be "HD Graphics 4400".
Good news: David Airlie's "drm-i915-mst-support" branch (http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-i915-mst-support) has solved the problem! :) Will those patches be part of Linux 3.16?
(In reply to comment #8) > Good news: David Airlie's "drm-i915-mst-support" branch > (http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-i915-mst-support) has > solved the problem! :) > > Will those patches be part of Linux 3.16? No. Not sure about 3.17 either. *** This bug has been marked as a duplicate of bug 72795 ***
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