Laptop DisplayPort and xrandr how to connect?

BW-userx · 06-16-2019, 09:10 PM

I got this

Code:

~ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
eDP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.05*+  59.93  
   1680x1050     59.88  
   1400x1050     59.98  
   1600x900      60.00    59.95    59.82  
   1280x1024     60.02  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1368x768      60.00    59.88    59.85  
   1280x800      59.81    59.91  
   1280x720      59.86    60.00    59.74  
   1024x768      60.00  
   1024x576      60.00    59.90    59.82  
   960x540       60.00    59.63    59.82  
   800x600       60.32    56.25  
   864x486       60.00    59.92    59.57  
   640x480       59.94  
   720x405       59.51    60.00    58.99  
   640x360       59.84    59.32    60.00  
DP1 disconnected (normal left inverted right x axis y axis)
DP2 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)

Code:

~ xrandr | grep connect
eDP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 310mm x 170mm

so that eDP1 is the one I should be trying to get xrandr to use to connect it to a monitor?

I don't have this monitor here with me, so I am just asking so when I am where it is at I can try connecting it to watch suff, of course.

what I've seen is things like this

Code:

xrandr --output HDMI-1 --mode 1920x1080 --pos 0x0

and this monitor has multiple HDMI ports that need to be selected with its remote control.

so just for clarity,

plug it in find the connection I am using with the remote control, then use xrandr in a terminal something like this to connect it to the monitor, and vola its works?

Code:

xrandr --output eDP1 --mode 1920x1080 --pos 0x0

THe specs for this laptop say,

Code:

 DisplayPort
Supports resolutions up to 3840 x 2160 at 60Hz. Supports Multi-Stream Transport (MST) where three 
displays can be daisy chained with digital displays through DisplayPort Only. The full resolution of 
each display will be limited as you reach 3 displays due to the bandwidth limitations with a maximum 
resolution of:

    2560 x 1600 at 60 Hz for 2 displays
    1920 x 1200 at 60 Hz for 3 displays

Number of Displays supported
3 With Optional* 2013 UltraSlim Docking Station

is it possible to change the monitor rez size or should it match the laptop max rez?

I do not want to mess anything up, especially the monitor because it is not mine.

mrmazda · 06-17-2019, 01:54 AM

Quote:

Originally Posted by BW-userx

so that eDP1 is the one I should be trying to get xrandr to use to connect it to a monitor?

eDP is Embedded DisplayPort, a video port permanently married to a display device inside the overall device (laptop, tablet, phone).

DPx and HDMIx are video ports either married to a connector to which a video cable and external display can be connected, or ports the GPU supports that have no attachment to a physical device (phantom).

Code:

# inxi -Gxx
Graphics:  Device-1: Intel HD Graphics 630 vendor: ASUSTeK driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:5912
           Display: tty server: X.Org 1.20.3 driver: modesetting unloaded: fbdev,vesa
           resolution: 2560x1440~60Hz, 2560x1080~60Hz, 1920x1200~60Hz
           OpenGL: renderer: Mesa DRI Intel HD Graphics 630 (Kaby Lake GT2) v: 4.5 Mesa 18.3.4 compat-v: 3.0
           direct render: Yes

The above 8086:5912 GPU used for the following only supports a maximum of three displays at a time.

Video port names/labels can be rather arbitrary:

Code:

# xrandr | grep -A2 onnec
DP-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 598mm x 336mm
   2560x1440     59.95*+  74.92
   1920x1440     75.00
--
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 2560x1080+2560+0 (normal left inverted right x axis y axis) 673mm x 284mm
   2560x1080     60.00*+
   1920x1080     60.00    60.00    50.00    59.94    24.00    23.98
--
HDMI-3 connected 1920x1200+5120+0 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200     59.95*+
   1680x1050     59.88
--/
DP-2 disconnected (normal left inverted right x axis y axis)

In the above, DP-1 is in fact attached to a DisplayPort connector/cable/display. HDMI-2 is in fact attached to a HDMI connector/cable/display. HDMI-3 is attached to a DVI-D port/cable/display. The GPU does have a 4th connector, VGA, which when connected is reported as DP-2. HDMI-1 is a phantom connector.

Each resolution above marked with *+ is that used by that display, and is the native resolution of that display. This has all been done via DDX driver and Xorg automagically, the choice of resolution coming from each display's EDID.

The layout of the above three displays is entirely horizontally: the left edge of the HDMI display adjacent to the right edge of the DisplayPort display, and the left edge of the DVI display adjacent to the right edge of the HDMI display. All three top edges aligned, thus you see 0 after the second + following each "connected".

The above horizontal arrangement is Xorg's default. Various tools can reposition displays arbitarily:

Code:

# xrandr | grep -A2 onnec
DP-1 connected primary 2560x1440+0+2280 (normal left inverted right x axis y axis) 598mm x 336mm
   2560x1440     59.95*+  74.92
   1920x1440     75.00
--
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 2560x1080+0+1200 (normal left inverted right x axis y axis) 673mm x 284mm
   2560x1080     60.00*+
   1920x1080     60.00    60.00    50.00    59.94    24.00    23.98
--
HDMI-3 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200     59.95*+
   1680x1050     59.88
--
DP-2 disconnected (normal left inverted right x axis y axis)

The above stacks the displays, with all their left edges aligned, DVI at top, DP at bottom, and HDMI in between. This is shown by 0 after the first + following each "connected". I did this with a startup xrandr script:

Code:

# xrandr --output DP-1 --mode 2560x1440 --primary --output HDMI-2 --mode 2560x1080 --above DP-1 --output HDMI-3 --mode 1920x1200 --above HDMI-2

so that the positions are in effect in the login greeter, so also at window manager startup. Arandr and other GUI tools are much more commonly used to place displays relative to each other, but their modus is usually xrandr.

Quote:

plug it in find the connection I am using with the remote control, then use xrandr in a terminal something like this to connect it to the monitor, and vola its works?

Most likely, when the display makes a connection to a laptop video port, you won't need xrandr unless you want its position to be different from its automatic placement (--above, --below, --right-of, --left-of; or using any arbitrary positioning), or you wish to designate another to be the primary display (showing panel, and being default display where apps start (--primary), or if you wish to scale (--dpi), or apply a different resolution (--mode); or if you use arandr or other GUI tool instead of xrandr.

Code:

# xrandr --output HDMI-3 --mode 1920x1200 --primary --output DP-1 --mode 2560x1440 --right-of HDMI-3 --output HDMI-2 --mode 2560x1080 --below DP-1

in a startup script produces the following:

Code:

# xrandr | grep -A2 onnec
DP-1 connected 2560x1440+1920+0 (normal left inverted right x axis y axis) 598mm x 336mm
   2560x1440     59.95*+  74.92
   1920x1440     75.00
--
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 2560x1080+1920+1440 (normal left inverted right x axis y axis) 673mm x 284mm
   2560x1080     60.00*+
   1920x1080     60.00    60.00    50.00    59.94    24.00    23.98
--
HDMI-3 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200     59.95*+
   1680x1050     59.88
--
DP-2 disconnected (normal left inverted right x axis y axis)

The two 2560 wide displays are stacked to the right of the 1920 wide display, which is primary and has the panel and whose top is aligned with the top of the two display stack to its right.

Quote:

Code:

xrandr --output eDP1 --mode 1920x1080 --pos 0x0

--pos 0x0 is probably where the laptop screen will show up by default, with the external display connection to its right. If both are 1920x1080 screens, then xrandr will probably show:

Code:

connected 1920x1080+1920+0

for the external display, and

Code:

eDP-1 connected 1920x1080+0+0

for the internal.

Quote:

is it possible to change the monitor rez size or should it match the laptop max rez?

Best to try first, giving automagic a chance to show what it can do. Once you know you might want to scale one's resolution up or the other's down if there is a big disparity in display density between the two screens.

BW-userx · 06-17-2019, 04:35 PM

Thanks, I was wondering if Linux was plug and play on this subject.