Two monitors, modelines, xorg.conf, and all that...

[Shannon McMackin]

On 06/03/2009 03:34 AM, Marko Vojinovic wrote:
> I have a laptop whose widescreen LVDS reports these modelines
> (correctly, afaik):
>
> (II) intel(0): Modeline "1280x800"x59.8   83.50  1280 1352 1480 1680
> 800 803 809 831 -hsync -vsync (49.7 kHz)
> (II) intel(0): Modeline "1024x768"x60.0   65.00  1024 1048 1184 1344
> 768 771 777 806 -hsync -vsync (48.4 kHz)
> (II) intel(0): Modeline "800x600"x60.3   40.00  800 840 968 1056  600
> 601 605 628 +hsync +vsync (37.9 kHz)
> (II) intel(0): Modeline "640x480"x59.9   25.18  640 656 752 800  480
> 490 492 525 -hsync -vsync (31.5 kHz)
>
> I also have a widescreen VGA monitor, reporting these:
>
> (II) intel(0): Modeline "1680x1050"x59.9  119.00  1680 1728 1760 1840
> 1050 1053 1059 1080 +hsync -vsync (64.7 kHz)
> (II) intel(0): Modeline "1680x1050"x60.0  146.25  1680 1784 1960 2240
> 1050 1053 1059 1089 -hsync +vsync (65.3 kHz)
> (II) intel(0): Modeline "1400x1050"x60.0  122.00  1400 1488 1640 1880
> 1050 1052 1064 1082 +hsync +vsync (64.9 kHz)
> (II) intel(0): Modeline "1280x1024"x75.0  135.00  1280 1296 1440 1688
> 1024 1025 1028 1066 +hsync +vsync (80.0 kHz)
> (II) intel(0): Modeline "1280x1024"x60.0  108.00  1280 1328 1440 1688
> 1024 1025 1028 1066 +hsync +vsync (64.0 kHz)
> (II) intel(0): Modeline "1440x900"x75.0  136.75  1440 1536 1688 1936
> 900 903 909 942 -hsync +vsync (70.6 kHz)
> (II) intel(0): Modeline "1440x900"x59.9  106.50  1440 1520 1672 1904
> 900 903 909 934 -hsync +vsync (55.9 kHz)
> (II) intel(0): Modeline "1280x960"x60.0  108.00  1280 1376 1488 1800
> 960 961 964 1000 +hsync +vsync (60.0 kHz)
> (II) intel(0): Modeline "1152x864"x75.0  108.00  1152 1216 1344 1600
> 864 865 868 900 +hsync +vsync (67.5 kHz)
> (II) intel(0): Modeline "1024x768"x75.0   78.75  1024 1040 1136 1312
> 768 769 772 800 +hsync +vsync (60.0 kHz)
> (II) intel(0): Modeline "1024x768"x70.1   75.00  1024 1048 1184 1328
> 768 771 777 806 -hsync -vsync (56.5 kHz)
> (II) intel(0): Modeline "1024x768"x60.0   65.00  1024 1048 1184 1344
> 768 771 777 806 -hsync -vsync (48.4 kHz)
> (II) intel(0): Modeline "832x624"x74.6   57.28  832 864 928 1152  624
> 625 628 667 -hsync -vsync (49.7 kHz)
> (II) intel(0): Modeline "800x600"x72.2   50.00  800 856 976 1040  600
> 637 643 666 +hsync +vsync (48.1 kHz)
> (II) intel(0): Modeline "800x600"x75.0   49.50  800 816 896 1056  600
> 601 604 625 +hsync +vsync (46.9 kHz)
> (II) intel(0): Modeline "800x600"x60.3   40.00  800 840 968 1056  600
> 601 605 628 +hsync +vsync (37.9 kHz)
> (II) intel(0): Modeline "800x600"x56.2   36.00  800 824 896 1024  600
> 601 603 625 +hsync +vsync (35.2 kHz)
> (II) intel(0): Modeline "640x480"x75.0   31.50  640 656 720 840  480
> 481 484 500 -hsync -vsync (37.5 kHz)
> (II) intel(0): Modeline "640x480"x72.8   31.50  640 664 704 832  480
> 489 492 520 -hsync -vsync (37.9 kHz)
> (II) intel(0): Modeline "640x480"x75.0   31.50  640 656 720 840  480
> 481 484 500 -hsync -vsync (37.5 kHz)
> (II) intel(0): Modeline "640x480"x59.9   25.18  640 656 752 800  480
> 490 492 525 -hsync -vsync (31.5 kHz)
> (II) intel(0): Modeline "720x400"x70.1   28.32  720 738 846 900  400
> 412 414 449 -hsync +vsync (31.5 kHz)
>
> When I plug in the VGA, X chooses the highest common resolution, which
> happens to be 1024x768. I can only ponder as to why a 22" VGA monitor
> does not want to do 1280x800, but that's not the question. What I
> would like to have is the following setup:
>
> * when VGA is not plugged in, LVDS should be up with its native
> resolution (1280x800)
> * when VGA is plugged in, LVDS should be off, while VGA in its native
> resolution (1680x1050)
>
> It would be nice to have this hot-pluggable, but I don't mind
> restarting X or the computer for the change. Can anybody tell me how
> to configure xorg.conf to make this happen?
>
> My current xorg.conf is fairly simple so far:
>
> ########################
> Section "ServerLayout"
>          Identifier     "X.org Configured"
>          Screen         "Screen0"
> EndSection
>
> Section "Device"
>          Option      "AccelMethod"  "XAA"
>          Identifier  "Card0"
>          Driver      "intel"
>          VendorName  "Intel Corporation"
>          BoardName   "Mobile GM965/GL960 Integrated Graphics Controller"
>          BusID       "PCI:0:2:0"
> EndSection
>
> Section "Screen"
>          Identifier "Screen0"
>          Device     "Card0"
> EndSection
> ########################
>
> The AccelMethod is set to XAA because of that famous intel random
> lockup thing (it doesn't eliminate the bug, just makes it more rare),
> everything else is autoconfigured.
>
> Thanks, :-)
> Marko
>
The display-settings applet should allow you to do this.  It won't be 
automatic, but it also won't take but a few mouse-clicks to do it. 
System - Preferences - Display.