Arch Linux

Striker

Member

Registered: 2017-07-06

Posts: 6

[SOLVED] Resolution reverts after turning TV off

Hello there,

I did a fresh Arch install today in my desktop with Xfce as the desktop environment since I really liked using it in my laptop for the last weeks. I'm using a TV as the only video output, connected through an HDMI cable to my computer, which has a Radeon R9 270 as its graphics board. Once everything was properly set up, I decided to try changing the resolution through xfce4-display-settings from 1280x720 to 1920x1080. Although the change gets applied at the moment and nothing unusual happens while the TV is on, as soon as a turn it off, then on again, it seems the changed settings are lost, and the display reverts back to 1280x720.

After two or three tests to confirm that this behavior happened repeatedly, I searched a bit, found this and while it's about Xfce on Debian, I tried applying the instructions in the first answer nonetheless, editing .config/xfce4/xfconf/xfce-perchannel-xml/displays.xml and changing the value of the "Resolution" property to "1920x1080". Below you can see what's inside the file

<?xml version="1.0" encoding="UTF-8"?>

<channel name="displays" version="1.0">
  <property name="Default" type="empty">
    <property name="HDMI-0" type="string" value="1. HB@ 32&quot;">
      <property name="Active" type="bool" value="true"/>
      <property name="Resolution" type="string" value="1920x1080"/>
      <property name="RefreshRate" type="double" value="60.000000"/>
      <property name="Rotation" type="int" value="0"/>
      <property name="Reflection" type="string" value="0"/>
      <property name="Primary" type="bool" value="false"/>
      <property name="Position" type="empty">
        <property name="X" type="int" value="0"/>
        <property name="Y" type="int" value="0"/>
      </property>
    </property>
  </property>
  <property name="Notify" type="bool" value="false"/>
</channel>

This still resulted in the same behavior when I turned the screen off and on again. I then decided using xrandr to modify the resolution:

xrandr --output HDMI-0 --mode 1920x1080

I also added this same line to ~/.initrc so it would be executed at xorg startup to see if it would somehow solve the problem, then rebooted. As expected, the display starts at 1920x1080 once I run startx, but resolution still reverts back to 1280x720 when I turn the TV off and on again. Since I'm unable to pinpoint both the cause and the solution to the problem, I decided to ask for help.

I'm unsure if this would be of any help, but I'm using the open-source AMD drivers listed on the wiki (not the Catalyst ones). If you want, here's the output of xrandr in the terminal as well:

Screen 0: minimum 320 x 200, current 1280 x 720, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1280x720+0+0 (normal left inverted right x axis y axis) 708mm x 398mm
   1280x720      60.00*+  50.00    59.94  
   1920x1080     60.00    50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1280x1024     75.02  
   1280x960      60.00  
   1360x768      59.95  
   1024x768      75.03    70.07    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  

Thanks in advance for any help.

Last edited by Striker (2017-07-06 07:22:03)

Striker

Member

Registered: 2017-07-06

Posts: 6

Re: [SOLVED] Resolution reverts after turning TV off

So, I was able to solve the problem by myself.

The solution: I created a 10-monitor.conf file in /etc/X11/xorg.conf and added the following lines to it:

Section "Monitor"
    Identifier  "HDMI-0"
    Option      "PreferredMode"  "1920x1080"
EndSection

If I understood what I did correctly, I set the "Preferred Mode" of "HDMI-0" (the TV I was using as monitor) to the mode with the resolution I wanted (1920x1080) in the xorg configuration. After that, I finished my session, then ran startx again, and from then on, the resolution was still the same after I turned the TV off and on again (1920x1080). The only nitpick I have is that this produces a strange xrandr output with "two" preferred modes (indicated by the "+" symbol), as can be seen below:

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 708mm x 398mm
   1920x1080     60.00*+  50.00    59.94  
   1280x720      60.00 +  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1280x1024     75.02  
   1280x960      60.00  
   1360x768      59.95  
   1024x768      75.03    70.07    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
DVI-0 disconnected (normal left inverted right x axis y axis)
DVI-1 disconnected (normal left inverted right x axis y axis)

But it works as I wanted, so I guess that's okay. Anyway, this thread can be locked since there's no further need for help, I guess.

Last edited by Striker (2017-07-06 07:21:47)