Xserver mode lists

[Matthias Hopf]

I do not claim to fully understand how modes lists are handled in the
server. In fact, I'm baffled more often than I understand something.


So far I know three sources of default modes:
- hw/xfree86/common/vesamodes
- hw/xfree86/common/extramodes
- hw/xfree86/modes/xf86EdidModes.c

I don't understand which of these files define modes for which purpose.
I can only see one reasonable purpose, to provide modes for the user
that are not explicitly defined by EDID from the display devices.


In these lists some of the more exotic (but probably more often used
in the future) modes are either missing (i.e. 1600x900, 1920x1080) or
represented by different modes (like 1366x768 by 1360x768).

Additionally, xf86EdidModes.c has special code for handling some of the
more weird cases (e.g. the infamous 1366x768), but AFAICS the code is
only used for analyzing the EDID data.

In my experiments 1360x768 is interpolated to 1366x768, and thus looks
dead ugly. 1366 itself is not dividable by 4, so in both GTF and CVT
this results in 1368x768. I do not claim to understand how this is
actually handled in both the Xserver and the displays :-/


So where should these additional modes go into? How to deal with modes
that are not dividable by 4 (how about odd sized ones: 1680x945)?


Matthias

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Matthias Hopf <mhopf at suse.de>      __        __   __
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