My MBP is dual booting LinuxMint 64-bit Cinnamon and Windows 8.
I have problem while setting up dual monitors on mint, everything except the monitor works great. Everything is updated.
There is only one resolution for my external monitor (640x480) while I'm on Windows 8 it works up to 1920x1080.
I tried to addmode with xrandr but it doesn't work.
Here is the result:
Thanks~ # xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
~ # xrandr
Screen 0: minimum 8 x 8, current 2080 x 900, maximum 8192 x 8192
LVDS-0 connected 1440x900+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
1440x900 59.9*+
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 connected 640x480+1440+0 (normal left inverted right x axis y axis) 0mm x 0mm
640x480 59.9*+
1920x1080_60.00 (0x26e) 173.0MHz
h: width 1920 start 2048 end 2248 total 2576 skew 0 clock 67.2KHz
v: height 1080 start 1083 end 1088 total 1120 clock 60.0Hz
~ # xrandr --addmode DP-1 1920x1080_60.00
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 18 (RRAddOutputMode)
Serial number of failed request: 29
Current serial number in output stream: 30