In lxrandr, laptop screen shrinks when hdmi screen is turned on

charles_houston · 2020-03-27 11:47:10

Right now I am using an external monitor through hdmi. Whenever I turn on the external monitor via lxrandr, the screen on my laptop is resized and shrunk. In the past I used xrandr to automate the configuration of an external monitor for a laptop with a a broken screen. Obviously I did not run into the same problem then. I don't think this is default behavior because it is undesirable when using multiple monitors simultaneously. Any insight would be appreciated.

Lone_Wolf · 2020-03-27 15:19:07

please post xrandr output with external monitor turned off, then turn it on and rerun xrandr.

Do the 2 monitors function as one big screen or show the same content twice ?

What videocard / driver are you using ?

Last edited by Lone_Wolf (2020-03-27 15:19:57)

charles_houston · 2020-03-29 14:08:36

When I do not have the HDMI turned on via lxrandr, the output of xrandr is

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 173mm 
   1920x1080     60.03*+  60.01    59.97    59.96    59.93  
   1680x1050     59.95    59.88  
   1400x1050     59.98  
   1600x900      59.99    59.94    59.95    59.82  
   1280x1024     60.02  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1280x800      59.99    59.97    59.81    59.91  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   640x400       59.88    59.98  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
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 (normal left inverted right x axis y axis)
   1280x720      60.00 +  59.94  
   1920x1080     60.00    59.94  
   1920x1080i    60.00    59.94  
   1440x480i     59.94  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       60.00    59.94

Now when I turn it on with lxrandr

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 173mm 
   1920x1080     60.03*+  60.01    59.97    59.96    59.93  
   1680x1050     59.95    59.88  
   1400x1050     59.98  
   1600x900      59.99    59.94    59.95    59.82  
   1280x1024     60.02  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1280x800      59.99    59.97    59.81    59.91  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   640x400       59.88    59.98  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
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 1280x720+0+0 (normal left inverted right x axis y axis) 920mm x 518mm 
   1280x720      60.00*+  59.94  
   1920x1080     60.00    59.94  
   1920x1080i    60.00    59.94  
   1440x480i     59.94  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       60.00    59.94

As you can see the only difference is the HDMI-2, but the computer display eDP-1 shrinks to the top left corner.

Also I can confirm this is not just a lxrandr problem because if I turn it on with

xrandr --output HDMI-2 --auto

the same problem occurs. My work around is to turn it off with lxrandr while connected or with

xrandr --output HDMI-2 --off

after I have disconnected.

But the problem remains that while connected, I can not fully use my computer's display.

As to my video card, this is the result of `lspci | grep VGA`

00:02.0 VGA compatible controller: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)

Trilby · 2020-03-29 14:15:25

So you are mirroriing: so both screens show the same content. The "resizing" is normal as the same content needs to be mapped to screens of different sizes. The other option would be for the HDMI screen to only show a portition of the desktop, which would be quite odd.

Far better options would be to extend the desktop using one of the --above --below --left-of or --right-of flags.

EDIT: I believe it might also be possible to using xrandr's scaling to put the same content full screen on both monitors, but the results of this have always seemed problematic.

Last edited by Trilby (2020-03-29 14:16:43)

Lone_Wolf · 2020-03-29 14:35:39

the xrandr outputs make clear HDMI-2 has a preferred resolution of 1280x720 while eDP-1 has 1920x1080.

Something on your system notices the difference and changes eDP-1 to display only the part that corresponds to the lower resolution part, but it doesn't change the resolution for eDP-1 .

are you using xf86-video-intel ?
If yes, try removing it so X will use the modesetting driver.

An alternative might be to force the external monitor to use same res as the internal screen.

Try enabling HDMI-2 with

xrandr --output HDMI-2 --mode 1920x1080

charles_houston · 2020-03-29 17:05:24

I am pretty sure I am using mesa. My system is mostly set up via an ansible project that I made. In that, the only driver I install seems to be from when I install xorg of which mesa is a dependency.

@Lone_Wolf I tried the command to make the hdmi screen the same as my default for the laptop. It worked but it is barely readable and is missing the edges. EDIT I think this has something to do with the TV but I dont have the remote

None of this is a big problem for me since I do not use the mirror setup. But now I understand why this behavior is happening.

@Trilby It would be interesting to get it to work with the scaling but it is not too important for me. I agree that extending the screen or using dual monitors makes more sense and confirm that it works on my system.

Last edited by charles_houston (2020-03-29 17:16:57)

ispanos · 2020-03-29 17:28:10

Can you try the following and tell me what happens?

xrandr --output eDP-1 --rotate normal -s 1920x1080 --output HDMI-2 --rotate normal --right-of HDMI-2 -s 1920x1080

Arch Linux

#1 2020-03-27 11:47:10

In lxrandr, laptop screen shrinks when hdmi screen is turned on

#2 2020-03-27 15:19:07

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

#3 2020-03-29 14:08:36

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

#4 2020-03-29 14:15:25

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

#5 2020-03-29 14:35:39

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

#6 2020-03-29 17:05:24

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

#7 2020-03-29 17:28:10

Re: In lxrandr, laptop screen shrinks when hdmi screen is turned on

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