[Gllug] Persuading X.org to give me the exact settings I asked for

[John Winters]

On Thu, 2005-12-29 at 11:36 +0000, Tethys wrote:
> John Winters writes:
> 
> >How can I persuade X that I really do want 1280x768 at the specified
> >frequency?
> 
> Creat a mode line for it. In theory, the X server should do this for you
> automatically, but the warning about the mode clock of 100000MHz is almost
> certainly causing this process to fail (or at least, give incorrect values).
> Try adding a suitable mode line manually:

I've been trying that.  With the aid of edid tools I've got:

        # EDID version 1 revision 3
Section "Monitor"
        # Block type: 2:0 3:fd
        # Block type: 2:0 3:fc
        Identifier "W1900 LCD TV"
        VendorName "DEL"
        ModelName "W1900 LCD TV"
        # Block type: 2:0 3:fd
        HorizSync 30-64
        VertRefresh 56-75
        # Max dot clock (video bandwidth) 110 MHz
        # Block type: 2:0 3:fc
        # Block type: 2:0 3:ff
        # DPMS capabilities: Active off:yes  Suspend:no  Standby:no

        Mode    "1280x768"      # vfreq 59.870Hz, hfreq 47.776kHz
                DotClock        79.500000
                HTimings        1280 1344 1472 1664
                VTimings        768 771 778 798
                Flags   "+HSync" "-VSync"
        EndMode
        # Block type: 2:0 3:fd
        # Block type: 2:0 3:fc
        # Block type: 2:0 3:ff
EndSection

but I still get that message:

(II) I810(0): Not using mode "1280x768" (no mode of this name)
(1280x768,W1900 LCD TV) mode clock 100000MHz exceeds DDC maximum 110MHz

The *really* odd thing is that these two error lines appear regardless
of whether I include the modeline for the mode.  They appear to be
triggered by the *use* of the mode and not by its definition.  It seems
to ignore my definition of the mode and use something internal which it
doesn't like.  The value of 100000MHz is particularly suspicious.  It
isn't the sort of value you get by calculation.

Is there any way of accessing it's own internal database of modelines to
see how they're defined?

I'm sure X configuration used to be much simpler when it was less
intelligent.

John

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