[SOLVED] Dual monitors daisychained, seen as one screen

svanberg · 2017-08-06 14:27:42

Hello!

I'm trying to set different background images on my dual monitor setup (Dell U2515H, daisychained), but for some reason Xorg sees this setup as one display (what I believe), as I can't e.g:

$ DISPLAY=:0.1 feh --bg-fill Downloads/04125_howlinatthemoon_2560x1440.jpg   
feh ERROR: Can't open X display. It *is* running, yeah?

Same thing happends, when I'm trying to start a program on the same monitor.

$ DISPLAY=:0.1 urxvt
urxvt: can't open display :0.1, aborting.

While changing 1 to 0 works just fine. Moving windows between the monitors or maximizing or minimizing is not an issue. Can I somehow identify my displays while running Xorg? Is it possible to export the current autogenerated configuration from Xorg (xorg.conf doesn't exist)? I have also tried to manually create Xorg configuration files, but with no sucess. Can someone point me in the right direction? Thanks!

$DISPLAY

$ $DISPLAY
bash: :0.0: command not found

/etc/X11/xorg.conf.d/10-monitor.conf

Section "Monitor"
    Identifier             "Monitor0"
EndSection

Section "Monitor"
    Identifier             "Monitor1"
EndSection

Section "Device"
    Identifier             "Device0"
    Driver                 "intel" #Choose the driver used for this monitor
#    BusID                  "PCI:0:2:0"
EndSection

Section "Device"
    Identifier             "Device1"
    Driver                 "intel" #Choose the driver used for this monitor
#    BusID                  "PCI:0:2:0"
EndSection

Section "Screen"
    Identifier             "Screen0"  #Collapse Monitor and Device section to Screen section
    Device                 "Device0"
    Monitor                "Monitor0"
    DefaultDepth           16 #Choose the depth (16||24)
    SubSection             "Display"
        Depth              16
        Modes              "2560x1440_60.00" #Choose the resolution
    EndSubSection
EndSection

Section "Screen"
    Identifier             "Screen1"  #Collapse Monitor and Device section to Screen section
    Device                 "Device1"
    Monitor                "Monitor1"
    DefaultDepth           16 #Choose the depth (16||24)
    SubSection             "Display"
        Depth              16
        Modes              "2560x1440_60.00" #Choose the resolution
    EndSubSection
EndSection

Last edited by svanberg (2018-02-03 21:10:50)

Lone_Wolf · 2017-08-06 15:13:24

That 10-monitor.conf does very littlle except assigning intel driver and setting 16 bit color depth .

Why you want only 16 bit color on a 2560x1440 screen is beyond me, but it shouldn't pose problems .
The iintel driver setting however could.

rename/move 10-monitor.conf , restart X .
post xrandr -q output .

svanberg · 2017-08-06 15:37:32

Lone_Wolf wrote:

That 10-monitor.conf does very littlle except assigning intel driver and setting 16 bit color depth .
Why you want only 16 bit color on a 2560x1440 screen is beyond me, but it shouldn't pose problems .
The iintel driver setting however could.
rename/move 10-monitor.conf , restart X .
post xrandr -q output .

Sorry If i wasn't clear enough, the Xorg configuration files was just a test to see if I could create a secondary screen for Xorg, of course I would use all available color spectrum with my brand new monitors.

$ xrandr -q
Screen 0: minimum 8 x 8, current 1024 x 768, maximum 32767 x 32767
DP1 disconnected primary (normal left inverted right x axis y axis)
DP1-1 disconnected (normal left inverted right x axis y axis)
DP1-1-1 disconnected (normal left inverted right x axis y axis)
DP1-1-8 connected 1024x768+0+0 (normal left inverted right x axis y axis) 550mm x 310mm
   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      75.03*   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 1024x768+0+0 (normal left inverted right x axis y axis) 550mm x 310mm
   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      75.03*   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  
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

.fluxbox/startup

xrandr --output VIRTUAL1 --off --output DP2 --off --output DP1 --off --output DP1-1-8 --primary --mode 2560x1440 --rate 60 --pos 0x0 --rotate normal --output HDMI1 --off --output DP1-1-1 --off --output DP1-1 --off --output DP1-8 --mode 2560x1440 --rate 60 --pos 2560x0 --rotate normal &

Thanks!

Last edited by svanberg (2017-08-06 15:37:53)

Lone_Wolf · 2017-08-07 14:39:46

I've re-read the Multihead woki page, and it's getting clearer.

The xrandr command you use does tell X it should combine those 2 monitors into one big screen.

You should be able to treat those monitors as indeppenednt screens, but that may mean you can't (easily) move things from one screen to another.

If you want to try, disable the xrandr startup command , re-start X and run xrandr -q again.
If it only shows 1 monitor active, you may need to start a 2nd X server on the other monitor.

svanberg · 2017-08-08 11:06:42

It seems that if I use xrandr to combine to one big screen ($DISPLAY will still output DISPLAY=:0.0), it's up to my window manager or software to detect if I have two or more monitors connected, e.g. Fluxbox will give me option to move windows between Head 1 and Head 2. After putting in the right search in Google, I found out that it was really simple applying different backgrounds for my setup, at least with Feh:

feh --bg-fill backgroundforscreen1.jpg --bg-fill backgroundforscreen2.jpg

Well as this is not issue to my anymore, I consider this solved.

Lone_Wolf wrote:

If you want to try, disable the xrandr startup command , re-start X and run xrandr -q again.
If it only shows 1 monitor active, you may need to start a 2nd X server on the other monitor.

As you stated, If I run X without xrandr, I only get picture on the first monitor. If I really want a secondary screen, how do I achive this? Thanks!

Last edited by svanberg (2017-08-08 11:08:32)

Lone_Wolf · 2017-08-08 12:57:33

I'll need to see the xorg log & and xrandr -q from an X start without the fluxbox xrandr startup command to determine how to proceed.

I do think it would be better to start a new thread for that.

Arch Linux

#1 2017-08-06 14:27:42

[SOLVED] Dual monitors daisychained, seen as one screen

#2 2017-08-06 15:13:24

Re: [SOLVED] Dual monitors daisychained, seen as one screen

#3 2017-08-06 15:37:32

Re: [SOLVED] Dual monitors daisychained, seen as one screen

#4 2017-08-07 14:39:46

Re: [SOLVED] Dual monitors daisychained, seen as one screen

#5 2017-08-08 11:06:42

Re: [SOLVED] Dual monitors daisychained, seen as one screen

#6 2017-08-08 12:57:33

Re: [SOLVED] Dual monitors daisychained, seen as one screen

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