No VESA VBE DDC data on Linux / X / KDE boot --> bad DPI value --> font too big

Jeff B JeffBatHome at myLetters.US
Mon Dec 7 16:17:17 PST 2009


Thanks for the prompt reply.

> Alex Deucher wrote:
> If the vesa driver is not able to get an edid from the monitor it has
> no way of knowing the size of the display so it defaults to 96 dpi.


> So either the vbe get edid call is problematic on your card

This is happening on two different machines so that can't be the
case unless the cards in both machines got flaky at the same time.

> or your monitor has flakey ddc.  

I did consider that the monitor could be the point of failure on this,
but I don't think that's the case.  Why?  I have some other machines
connected to the same monitor which still run older Slackware versions
(and older X versions too) which are NOT seeing this problem.  Further,
the problem began right when I installed Slackware 12.2 (and its newer
X version) on the affected machines.

Those facts lead me to believe that the problem came in with Slackware
12.2.  Where the problem is in all that code I don't know, but the error
messages come from LIBVBE.SO.

> You may have better luck using a real driver for your hardware 
> rather than vesa.

I would prefer not to have to do that, obviously.  I'm not an IT guy.
I *am* a programmer, however, who has spent much time on HW
drivers and async code.  This whole thing just has the odor of a race
condition, uninitialized variable, or other such bug which can lead
to intermittent failure.  To patch around the problem for myself will
not eliminate bugs in the code affecting everyone.

Thanks again for your reply.

Jeff B.

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