我在笔记本电脑上安装了Arch，但是我认为这个问题并不是Arch特有的。目前唯一的问题是未检测到连接到hdmi端口的显示器。例如，从gnome控制中心运行，即使有第二个监视器通过HDMI端口连接到笔记本电脑，显示小程序然后“检测”也只能检测到笔记本电脑的显示器。我怀疑问题是xrandr没有检测到连接到HDMI端口的监视器。我怎样才能解决这个问题？
lspci -v对于vga控制器的输出：
01:00.0 VGA compatible controller: nVidia Corporation Device 0df5 (rev a1) (prog-if 00 [VGA controller])
Subsystem: Dell Device 0446
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at f0000000 (32-bit, non-prefetchable) [size=16M]
Memory at c0000000 (64-bit, prefetchable) [size=256M]
Memory at d0000000 (64-bit, prefetchable) [size=32M]
I/O ports at 3000 [size=128]
Expansion ROM at f1000000 [disabled] [size=512K]
Capabilities: <access denied>
Kernel driver in use: nouveau
Kernel modules: nvidiafb, nouveau00:02.0 VGA compatible controller:
Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Subsystem: Dell Device 0446
Flags: bus master, fast devsel, latency 0, IRQ 49
Memory at f1400000 (64-bit, non-prefetchable) [size=4M]
Memory at e0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 4000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: <access denied>
Kernel driver in use: i915
Kernel modules: i915
xrandr的输出：
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
LVDS1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
1920x1080 60.0*+ 40.0
1400x1050 60.0
1280x1024 60.0
1280x960 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)