当我的辅助显示器在启动时插入时，如何才能使主显示器正常运行？

Question

如果我启动 Acer Aspire v5 笔记本电脑时插入辅助显示器 (hdmi)，我会在主显示器和辅助显示器上看到 POST 屏幕。在到达登录屏幕之前，我的主 (笔记本电脑) 显示器变黑，并且即使在登录后也保持黑屏，但辅助显示器工作正常。

我必须先拔下 HDMI 插头，然后才能打开机器、启动、登录，然后再重新插入，才能使用双屏设置。理想情况下，我根本不想拔下它。

这是一个新安装，ubuntu 16.04 64位，完全默认设置。

monitors.xml 似乎有重复的条目，我删除了该文件，配置了我的显示布局并应用它；

<monitors version="1">
<configuration>
      <clone>no</clone>
      <output name="eDP1">
          <vendor>AUO</vendor>
          <product>0x31ec</product>
          <serial>0x00000000</serial>
          <width>1366</width>
          <height>768</height>
          <rate>60</rate>
          <x>0</x>
          <y>0</y>
          <rotation>normal</rotation>
          <reflect_x>no</reflect_x>
          <reflect_y>no</reflect_y>
          <primary>yes</primary>
      </output>
      <output name="DP1">
      </output>
      <output name="HDMI1">
          <vendor>ACR</vendor>
          <product>0x02e9</product>
          <serial>0x30800bc8</serial>
          <width>1600</width>
          <height>900</height>
          <rate>60</rate>
          <x>1366</x>
          <y>0</y>
          <rotation>normal</rotation>
          <reflect_x>no</reflect_x>
          <reflect_y>no</reflect_y>
          <primary>no</primary>
      </output>
      <output name="VGA1">
      </output>
      <output name="VIRTUAL1">
      </output>
</configuration>
</monitors>

其他相关信息；

$ xrandr -q
Screen 0: minimum 8 x 8, current 2966 x 900, maximum 32767 x 32767
eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1366x768      60.10*+
   1360x768      59.80    59.96  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   680x384       60.00  
   640x360       60.00  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 connected 1600x900+1366+0 (normal left inverted right x axis y axis) 442mm x 249mm
   1600x900      60.00*+
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   640x480       75.00    72.81    66.67    60.00  
   720x400       70.08  
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

更多信息;

# lspci  -v -s  $(lspci | grep VGA | cut -d" " -f 1)
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
    Subsystem: Acer Incorporated [ALI] 3rd Gen Core processor Graphics Controller
    Flags: bus master, fast devsel, latency 0, IRQ 28
    Memory at f0000000 (64-bit, non-prefetchable) [size=4M]
    Memory at e0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 3000 [size=64]
    Expansion ROM at <unassigned> [disabled]
    Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
    Capabilities: [d0] Power Management version 2
    Capabilities: [a4] PCI Advanced Features
    Kernel driver in use: i915
    Kernel modules: i915

任何见解都将不胜感激，我对完整桌面的经验非常有限，多年来大多使用远程 shell，谢谢。^_^