re-probing DDC/EDID

[perryh at pluto.rain.com]

Robert Noland <rnoland at FreeBSD.org> wrote:
> On Thu, 2009-05-21 at 23:38 -0700, perryh at pluto.rain.com wrote:
> > Is there any way to re-probe the monitor's DDC/EDID while the
> > X server is running?
...
> xrandr?

That seems to return the set of resolutions probed at startup
(i.e. those of the old monitor):

$ xrandr -q
   SZ:    Pixels          Physical       Refresh
  *0   1280 x 1024   ( 342mm x 271mm )  *60  
   1   1024 x 768    ( 342mm x 271mm )   60  
   2    800 x 600    ( 342mm x 271mm )   60  
   3    640 x 480    ( 342mm x 271mm )   60  
   4   1280 x 960    ( 342mm x 271mm )   60  
   5   1152 x 864    ( 342mm x 271mm )   75  
   6   1152 x 768    ( 342mm x 271mm )   55  
   7    832 x 624    ( 342mm x 271mm )   75  
   8    700 x 525    ( 342mm x 271mm )   75   60  
   9    640 x 512    ( 342mm x 271mm )   75   60  
   10   576 x 432    ( 342mm x 271mm )   75  
   11   576 x 384    ( 342mm x 271mm )   55  
   12   512 x 384    ( 342mm x 271mm )   75   70   60  
   13   416 x 312    ( 342mm x 271mm )   75  
   14   400 x 300    ( 342mm x 271mm )   75   72   60   56  
   15   320 x 240    ( 342mm x 271mm )   75   73   60  
  Current rotation - normal
  Current reflection - none
  Rotations possible - normal 
  Reflections possible - none

If the list were for the new monitor it would include 1920x1200.

Also, I'm looking for the whole collection of settings to include in
at least the highest-resolution modeline for the new monitor, such
as this entry (which was probed with the old monitor connected -- it
works on the new one, but doesn't utilize the higher resolution that
should now be available):

  Modeline "1280x1024"  108.00  1280 1328 1440 1688  1024 1025 1028 1066 +hsync +vsync

Based on the new monitor's manual, it should support:

  #   resolution  H KHz  V Hz

  1   640 x  350   31.4  70.0
  2   720 x  400   31.4  70.0
  3   640 x  480   31.4  59.9
  4   640 x  480   37.5  75.0
  5   800 x  600   35.1  56.2
  6   800 x  600   37.8  60.3
  7   800 x  600   46.8  75.0
  8   832 x  624   49.7  74.5
  9  1024 x  768   48.3  60.0
 10  1024 x  768   56.4  70.0
 11  1024 x  768   60.0  75.0
 12  1152 x  864   67.5  60.0
 13  1152 x  870   68.6  75.0
 14  1280 x  960   60.0  60.0
 15  1280 x 1024   63.9  60.0
 16  1280 x 1024   79.9  75.0
 17  1440 x  900   55.9  60.0
 18  1680 x 1050   64.7  60.0
 19  1600 x 1200   75.0  60.0
 20  1920 x 1200   74.0  59.9

but that doesn't give me the dot-clock frequencies, the 2nd-4th
horizontal and vertical counts, nor the sync polarities.