我的笔记本电脑上运行着 Ubuntu 14.04。由于我的笔记本电脑屏幕坏了，我给这台笔记本电脑连接了一个 VGA 显示器（Acer）。
一切都很好，直到有一天我的显示器变黑了，我不得不重新启动笔记本电脑。
当我获得 GUI 后，我发现我的辅助 VGA 显示器不工作。Ubuntu 无法将分辨率设置为更高的 16:9。
似乎无法找到该辅助显示器的正确驱动程序。
以下是 dmesg 的输出。
[ 20.877170] sony_laptop: Sony Notebook Control Driver v0.6
[ 20.877386] input: Sony Vaio Keys as /devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/SNY5001:00/input/input7
[ 20.885435] input: Sony Vaio Jogdial as /devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/SNY5001:00/input/input8
[ 20.888589] wmi: Mapper loaded
[ 20.904629] [drm] Memory usable by graphics device = 2048M
[ 20.904635] checking generic (b0000000 410000) vs hw (b0000000 10000000)
[ 20.904637] fb: conflicting fb hw usage inteldrmfb vs VESA VGA - removing generic driver
[ 20.904657] Console: switching to colour dummy device 80x25
[ 20.923223] lp: driver loaded but no devices found
[ 20.938996] ppdev: user-space parallel port driver
[ 20.962842] i915 0000:00:02.0: irq 44 for MSI/MSI-X
[ 20.962854] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 20.962855] [drm] Driver supports precise vblank timestamp query.
[ 20.962912] vgaarb: device changed decodes: PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem
[ 20.999456] kvm: disabled by bios
[ 21.008370] [drm] Wrong MCH_SSKPD value: 0x16040307
[ 21.008374] [drm] This can cause pipe underruns and display issues.
[ 21.008375] [drm] Please upgrade your BIOS to fix this.
[ 21.039348] fbcon: inteldrmfb (fb0) is primary device
请帮我解决这个问题！
谢谢你！
更新：我运行了命令xrandr --output VGA1 --mode 1600x900，现在分辨率没问题了。但现在我看到两个屏幕合二为一。我的主笔记本电脑显示器不工作，所以我使用辅助 VGA 显示器。但现在两个屏幕合二为一，因此顶部的任务栏重叠了。
现在命令的输出xrandr如下：
Screen 0: minimum 320 x 200, current 1600 x 900, maximum 32767 x 32767
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 345mm x 194mm
1366x768 60.0*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 connected primary 1600x900+0+0 (normal left inverted right x axis y axis) 443mm x 249mm
1600x900 60.0*+
1280x800 59.8
1152x864 75.0
1280x720 60.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 66.7 60.0
720x400 70.1
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
我已附上此截图：
