Bug#764990: Update about DisplayPort MST displays
I just found out an interesting thing. The displays are indeed detected,
but are not added by xorg, instead they are removed.
This is a log from undocking:
[ 840.894] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-5 (null)
[ 840.897] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 840.897] (II) intel(0): Printing DDC gathered Modelines:
[ 840.897] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 840.928] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-4 (null)
[ 840.928] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 840.928] (II) intel(0): Printing DDC gathered Modelines:
[ 840.928] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 840.965] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 840.965] (II) intel(0): Printing DDC gathered Modelines:
[ 840.965] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 840.996] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-3 (null)
[ 840.996] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 840.996] (II) intel(0): Printing DDC gathered Modelines:
[ 840.996] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
And this is from docking:
[ 845.199] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-3 (null)
[ 845.202] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 845.202] (II) intel(0): Printing DDC gathered Modelines:
[ 845.202] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 845.232] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-4 (null)
[ 845.232] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 845.232] (II) intel(0): Printing DDC gathered Modelines:
[ 845.232] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 845.269] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 845.269] (II) intel(0): Printing DDC gathered Modelines:
[ 845.269] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
[ 845.300] removing GPU device
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-DP-5 (null)
[ 845.300] (II) intel(0): EDID vendor "LGD", prod id 1079
[ 845.300] (II) intel(0): Printing DDC gathered Modelines:
[ 845.300] (II) intel(0): Modeline "1920x1080"x0.0 138.46 1920 1968
2000 2106 1080 1083 1088 1095 +hsync -vsync (65.7 kHz eP)
In both cases the DP-[3-5] devices are "removed". Why are they being
removed when docking? A bug?
Also, throughout all of that none of these displays are reported by
xrandr and cannot be used unless the xserver is restarted. Only then are
they added properly.
Cheers,
Jacob
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