Noah Sombrero composed on 2022-04-03 08:40 (UTC-0400):
> Thanks. I did find suggestions like this online. But it appears that
> xorg.conf is no longer used, and is indeed missing from xorg.conf.d.
> So I can simply create a new file with these entries and put it in
> place?
/etc/X11/xorg.con* are optional. They are available for use if and when
automagic
is not working. Before going through the manual configuration routine, let's
first
see what is actually happening. Please provide output from the following:
cat /var/log/Xorg.0.log | pastebinit
>>Section "Monitor"
>> Identifier "Monitor-HDMI1"
>> VendorName "LGD"
>> ModelName "ULTRAWIDE"
>> Modeline "2560x1080" 185.580 2560 2624 2688 2784 1080 1083 1093 1111
>> -HSync -VSync
>> Option "PreferredMode" "2560x1080"
>>EndSection
GTF and CVT can be used to generate a modeline, but their results will be no
better than the modeline X will generate automatically if given the proper data
to
substitute for EDID failure.
>>Via xrandr instead, applying such a thing would look like this:
>>xrandr --newmode "2560x1080" 185.580 2560 2624 2688 2784 1080 1083 1093 1111
>>-HSync -VSync
>>xrandr --addmode HDMI1 "2560x1080"
>>xrandr --output HDMI1 --mode "2560x1080"
>>So that's the how. The what is best explained by this web page:
>>https://arachnoid.com/modelines/
>>Which should be enough for you to work out the specific timings
>>needed to get this screen to work.
Xorg is fully competent to generate needed modelines, given the right
information.
Normally that information comes from EDID. If EDID is broken, or not reaching
Xorg, substitute information can provided via /etc/X11/xorg.con*.
hwinfo --monitor
should generate lines similar to these:
Vert. Sync Range: 24-75 Hz
Hor. Sync Range: 26-81 kHz
These can be used in a config file, e.g. /etc/X11/xorg.conf.d/50-monitor.conf,
containing:
Section "Monitor"
Identifier "DefaultMonitor"
VendorName "MyBrand"
ModelName "MyModel"
HorizSync 26-81
VertRefresh 24-75
Option "PreferredMode" "1920x1080"
EndSection
This, appropriately adjusted to include the numbers for the specific display, is
all the information Xorg usually needs to emulate the EDID information that
apparently doesn't get processed correctly for whatever reason. Others may
suggest
a modeline is needed, but independent modeline generators rarely do any better
calculating than Xorg does automatically, if & when given the needed data as
above
suggested. I've been using HorizSync and VertRefresh with difficult environments
for well over a decade, and never have needed a pre-configured modeline. When
configured with HorizSync and VertRefresh, instead of with a modeline, very
likely
plugging in a different display at some future time won't result in unusable
output that inhibits removing or editing the .conf file containing the modeline.
--
Evolution as taught in public schools is, like religion,
based on faith, not based on science.
Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!
Felix Miata
