xrandr 说“在可用模式下未找到尺寸 1920x1200”，尽管它可用

Question

当我在 KDE (Debian 9 amd64) 中手动将分辨率降低1920x1200到某个较低分辨率时，命令

xrandr -s 1920x1200

...不起作用：

% xrandr -s 1920x1200
Size 1920x1200 not found in available modes

1920x1200嗯，实际上尺寸可用：

% xrandr -q
Screen 0: minimum 8 x 8, current 1920 x 1200, maximum 32767 x 32767
HDMI-0 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
   1920x1200     59.95*+
   1920x1080     60.00    59.94    50.00    60.00    50.04  
   1680x1050     59.95  
   1600x1200     60.00  
   1440x900      59.89  
   1280x1024     60.02  
   1280x960      60.00  
   1280x720      60.00    59.94    50.00  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x480       59.94  
   640x480       59.94    59.93  
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)

设置每个答案的输出https://superuser.com/a/1257312/200129没有帮助：

• 当我1920x1200设置分辨率时，执行命令xrandr -s 1920x1200会使屏幕闪烁。

• 当我设置较低的分辨率并将输出监视器添加到类似命令时xrandr --output HDMI-0 -s 1920x1200，什么也没有发生 - 甚至屏幕也没有闪烁。

PS 命令xrandr -s 0设置模式1920x1080，即第二模式。