Displayport daisy chained displays get recognized as the same
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Confirmed
|
Medium
|
Unassigned | ||
Xenial |
Confirmed
|
Medium
|
Unassigned |
Bug Description
Hi,
I'm using Ubuntu 16.04.2 LTS.
Since I upgraded to 4.4.0-77, my daisy chained displays seem to get recognized as the same. Before, I've been using 4.4.0-72. Booting the older Kernel using grub also still works.
I'm using two Dell U2715H Displays daisy chained. (DP1-1 and DP1-8) Both with 2560x1440px. Simultaneously, I use my Notebook Display with 1920x1080px. (eDP1) I have a script, which I run manually after startx, which sets up my environment. It does:
xrandr --output DP1-1 --mode 2560x1440
xrandr --output DP1-8 --mode 2560x1440
xrandr --output DP1-8 --left-of eDP1
xrandr --output DP1-1 --left-of DP1-8
On 4.4.0-77 both, DP1-1 and DP1-8 show the same picture (left-of eDP1);
whereas on 4.4.0-72,
DP1-1 shows the picture left of DP1-8,
and DP1-8 shows the picture left of eDP1
as expected.
If I take a screenshot using xfce4-screensho
I attached the output from xrandr on both kernels, screenshots from both pictures and reference pictures taken with my camera for you to see what actually happens.
Thanks.
Screen 0: minimum 8 x 8, current 7040 x 1440, maximum 32767 x 32767
eDP1 connected 1920x1080+5120+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
1600x900 60.00
1280x1024 60.02
1440x900 59.89
1280x960 60.00
1368x768 60.00
1360x768 59.80 59.96
1152x864 60.00
1280x720 60.00
1024x768 60.00
1024x576 60.00
960x540 60.00
800x600 60.32 56.25
864x486 60.00
640x480 59.94
720x405 60.00
640x360 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP1-1 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
2560x1440 59.95*+
2048x1152 60.00
1920x1200 59.88
1920x1080 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1600x1200 60.00
1680x1050 59.95
1280x1024 75.02 60.02
1200x960 59.99
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.08 60.00
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
DP1-8 connected 2560x1440+2560+0 (normal left inverted right x axis y axis) 597mm x 336mm
2560x1440 59.95*+
2048x1152 60.00
1920x1200 59.88
1920x1080 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1600x1200 60.00
1680x1050 59.95
1280x1024 75.02 60.02
1200x960 59.99
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.08 60.00
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-
ProcVersionSign
Uname: Linux 4.4.0-77-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/pcmC1D0c: florian 2980 F...m pulseaudio
/dev/snd/pcmC1D0p: florian 2980 F...m pulseaudio
/dev/snd/
Date: Tue May 9 11:27:40 2017
HibernationDevice: RESUME=
InstallationDate: Installed on 2015-08-01 (646 days ago)
InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: Notebook W740SU
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.157.8
SourcePackage: linux
UpgradeStatus: Upgraded to xenial on 2016-06-12 (330 days ago)
dmi.bios.date: 08/13/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.5
dmi.board.
dmi.board.name: W740SU
dmi.board.vendor: Notebook
dmi.board.version: Not Applicable
dmi.chassis.
dmi.chassis.type: 9
dmi.chassis.vendor: Notebook
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: W740SU
dmi.product.
dmi.sys.vendor: Notebook
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