我不久前在我的筆記型電腦上安裝了 arch linux，一切正常。我自兩週左右以來一直面臨的問題（最肯定與更新有關）在附加外部顯示器登錄時發生（登錄[[ -z $DISPLAY && $XDG_VTNR -eq 1 ]] && exec startx通過運行.zshrc）：.xinitrc運行randrctl auto（這只是 的包裝器xrandr）以檢測連接的顯示器和根據需要配置它們。這會出現一個錯誤提示，表示所需的模式不適用於顯示器：
ERROR /usr/bin/xrandr: cannot find mode 1680x1050
WM（順便說一下 i3）啟動後立即運行 xrandr 顯示以下輸出：
date; xrandr
Thu Nov 5 10:15:03 CET 2015
Screen 0: minimum 8 x 8, current 1600 x 900, maximum 32767 x 32767
eDP1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
1600x900 60.05*+
1368x768 60.00
1280x720 60.00
...
720x405 60.00
640x360 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP2-1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1440x900 59.90*+
DP2-2 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1440x900 59.90*+
DP2-3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
這解釋了錯誤，因為 DP2-1 和 DP2-2 可用的模式不是我想要應用的模式。
大約 15 秒後，輸出改變：
date; xrandr
Thu Nov 5 10:15:16 CET 2015
Screen 0: minimum 8 x 8, current 1600 x 900, maximum 32767 x 32767
eDP1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
1600x900 60.05*+ 40.04
1368x768 60.00
1280x720 60.00
...
720x405 60.00
640x360 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP2-1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1680x1050 59.95 +
1280x1024 75.02 60.02
1440x900 59.90*
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
DP2-2 connected 1440x900+0+0 (normal left inverted right x axis y axis) 433mm x 271mm
1680x1050 59.95 +
1280x1024 75.02 60.02
1440x900 59.90*
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
DP2-3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
現在正如預期的那樣。為什麼需要這麼長時間？
一些附加資訊：
X.Org X Server 1.17.1
X.Org ANSI C Emulation: 0.4
X.Org Video Driver: 19.0
X.Org XInput driver : 21.0
X.Org Server Extension : 9.0
Kernel: Linux 1040 4.2.5-1-ARCH #1 SMP PREEMPT Tue Oct 27 08:13:28 CET 2015 x86_64 GNU/Linux