Side note about wrong monitor size [was Re: New monitor, pink vertical line ...]

[Alex Deucher]

On Sun, Feb 28, 2010 at 9:07 AM, Dave Witbrodt <dawitbro at sbcglobal.net> wrote:
>> 5) xdpyinfo reports this (notice particularly the size in millimeters):
>>
>> screen #0:
>>  dimensions:    1920x1200 pixels (508x317 millimeters)
>>  resolution:    96x96 dots per inch
>>
>> while Xorg.0.log includes this:
>
> [...]
>>
>> (II) RADEON(0): clock: 154.0 MHz   Image Size:  593 x 371 mm
>
> [...]
>>
>> This is what I have in xorg.conf for the monitor:
>>
>> Section  "Monitor"
>>        Identifier      "HH281HPB"
>>        VendorName      "Hanns.G"
>>        ModelName       "HH281HPB"
>>        HorizSync       24-80
>>        VertRefresh     56-75
>>        DisplaySize     593     371
>>        Option          "DPMS"
>> EndSection
>>
>> Apparently 'xdpyinfo' has a mind of its own!  ;)
>
> Culprit is something in 'radeon':
>
> # grep 'Image Size:' /var/log/Xorg.0.log | uniq
> (II) RADEON(0): clock: 154.0 MHz   Image Size:  593 x 371 mm
>

This is from the edid.

> # grep 'screen physical' /var/log/Xorg.0.log
> (II) RADEON(0): Setting screen physical size to 508 x 317

This is from the xserver.  The display size is all handled in the
xserver rather than the driver.  All the driver does is pass the edid
along.  Recent xservers default to 96 dpi.

Alex