16:9 ratio for lower resolutions

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1

I am trying to use my laptop with a second screen. For this I’d like to reduce the resolution of my laptop such that it matches with the 2nd screen. The problem is that only the highest resolution offered is 16:9 and all others are 4:3, such that there are always two black bars on my laptop. This is my xrandr output:

> $ xrandr  
Screen 0: minimum 320 x 200, current 3080 x 1050, maximum 8192 x 8192
eDP-1 connected primary 1400x1050+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
   2560x1440     60.00 +
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   1600x1200     60.00  
   1400x1050     59.98* 
   1280x1024     60.02  
   1280x960      60.00  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   800x600       60.00    60.32    56.25  
   700x525       59.98  
   640x512       60.02  
   640x480       60.00    59.94  
   512x384       60.00  
   400x300       60.32    56.34  
   320x240       60.05  
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 1680x1050+1400+0 (normal left inverted right x axis y axis) 474mm x 297mm
   1680x1050     59.88*+
   1280x1024     60.02  
   1280x960      60.00  
   1280x720      60.00  
   1024x768      60.00  
   800x600       60.32  
   640x480       59.94

As you can see the upper screen eDP-1 only has one 16:9 resolution to offer, where the other has multiple ratios to offer. How can I add a 1920x1080 resolution for my laptop? These used to exists for other Linux distros.

Kind regards

Matthias

2

It is not Linux that decides it is a function of what the screen reports to the OS.

3

My previous Arch & Ubuntu installations worked fine. I don’t think they got different reports. So it has to be related to Linux somehow.

4

The underlying video driver is responsible for obtaining the EDID information from the display device. Sometimes that information is incomplete (or incorrect) of course. I don’t generally recommend using anything other than the native display mode as you’ll find the resulting image will not be sharp, however if you want to experiment with configuring 1920x1080 using xrandr (assuming that your hardware really can support that display mode) then read on…

Get the timing data via cvt…

cvt 1920 1080
# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

then do

xrandr --newmode  "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

xrandr --addmode eDP-1 1920x1080_60.00

 xrandr --output eDP-1 --mode 1920x1080_60.00

Any errors?

If that works as desired, you can make it persistent via an ‘autostart’ script executed at login.

A guide…
https://wiki.archlinux.org/index.php/xrandr#Adding_undetected_resolutions