Question about screen resolution in plasma 5 using x11 and a 4 K monitor arrangement.
Duncan
1i5t5.duncan at cox.net
Tue Mar 15 06:36:26 GMT 2022
Stakanov posted on Mon, 14 Mar 2022 16:26:02 +0100 as excerpted:
> In data lunedì 14 marzo 2022 12:49:29 CET, Duncan ha scritto:
>> Another suggestion: Try running xrandr (without options should be
>> fine) in a konsole window, and see if it lists 3840x2160 there. If you
>> see the option there, X should be able to do it and it's probably a
>> kde-plasma thing. If the resolution isn't listed there, X doesn't
>> think it's possible either, and you'll need to figure out how to get X
>> to see it first. (There's several different ways to get and then feed
>> X the necessary modeline info; I always used a modeline generator,
>> there's some on the web as well as X utilities available, and setup the
>> xorg.conf config with it.)
> Infact, Xrandr gives:
> xrandr Screen 0: minimum 320 x 200, current 4944 x 1440, maximum 16384 x
> 16384 DisplayPort-0 connected 1920x1080+0+180 (normal left inverted
> right x axis y axis) 509mm x 286mm
> 1920x1080 60.00*+ 50.00 59.94
> 1600x1200 60.00
[snip lower resolutions]
> DisplayPort-1 disconnected (normal left inverted right x axis y axis)
> DisplayPort-2 disconnected (normal left inverted right x axis y axis)
> DisplayPort-3 connected primary 2560x1440+2384+0 (normal left inverted
> right x axis y axis) 698mm x 393mm
> 2560x1440 59.95 + 74.97*
> 1920x1200 59.88
[snip lower resolutions]
>
> So it thinks I cannot do it. But the specs say I can. That is strange.
> I will have to write Lenovo if this monitor was produced with charge
> that cannot do the resolution?
OK, so X isn't seeing the 3840x2160 as possible, at 60 or even the lower
end 30 Hz. So you gotta get X to see it, somehow.
Next step, can you find and post your xorg log? Look in ~/.local/share/
xorg/ file Xorg.0.log or similar, or if X is running as root, in /var/
log/.
That will normally have (among other data about the graphics card, the
driver for it, input devices and their drivers and settings, etc) a bunch
of lines for what the monitor says it can do (could be the problem) and
what X translates that to in its modeline style config (builtin if you've
not added any modelines manually).
Of particular interest is the EDID clained-supported resolutions from the
monitor, along with the reported probed modelines. I happen to have an
old xorg log still around from back in October (must have been the last
time I ran xorg). Here's what mine looks like from that (... indicates
snips):
...
[ 29.256] (II) AMDGPU(0): EDID for output HDMI-A-0
...
[ 29.257] (II) AMDGPU(0): First detailed timing is preferred mode
...
[ 29.257] (II) AMDGPU(0): Supported established timings:
[snipped the low-res standard legacy timings...]
...
[ 29.257] (II) AMDGPU(0): Supported standard timings:
[snipped the medium-res standard legacy timings...]
...
[ 29.257] (II) AMDGPU(0): Supported detailed timing:
[ 29.257] (II) AMDGPU(0): clock: 594.0 MHz Image Size: ...
[ 29.257] (II) AMDGPU(0): h_active: 3840 h_sync: 4016 ...
[ 29.257] (II) AMDGPU(0): v_active: 2160 v_sync: 2168 ...
*THAT* is actually the first detailed timing mentioned as the preferred/
native mode earlier. Note the h_active 3840, v_active 2160.
...
[ 29.257] (II) AMDGPU(0): Ranges: V min: 24 V max: 75 Hz, H min: 15 H
max: 135 kHz, PixClock max 605 MHz
*THAT* line has the numbers you'll need if you end up having to manually
add a modeline.
...
[ 29.258] (II) AMDGPU(0): Printing probed modes for output HDMI-A-0
[ 29.258] (II) AMDGPU(0): Modeline "3840x2160"x60.0 594.00 3840 4016
4104 4400 2160 2168 2178 2250 +hsync +vsync (135.0 kHz UeP)
[ 29.258] (II) AMDGPU(0): Modeline "4096x2160"x60.0 594.00 4096 4184
4272 4400 2160 2168 2178 2250 +hsync +vsync (135.0 kHz e)
*THAT* is then the first two of many modelines, X's translation of the
above EDID to in this case builtin settings that X can actually use. As
you will note, the second one is actually 4096x2160 at 60Hz. That's a
somewhat wider movie standard, I think, one that both X and the monitor
can display tho it's above native and slightly aspect-ratio-distorted.
...
But other lines may provide useful debugging info, so I'd suggest posting
the whole thing, after looking it over to ensure it's not got anything
sensitive/private in it, of course. Grabbing the log shortly after
starting a new session should yield the shortest file for posting, but
still have all the useful info.
--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman
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