Comment # 2 on bug 1193457 from Felix Miata

Created attachment 854393 [details]
dmesg from TW20211203

(In reply to Stefan Dirsch from comment #1)
> I guess running "xrandr --auto" doesn't change anything, right?

Wrong! I never thought to try it. :( It would have saved a lot of time.

Using it is progress, but as you can see, the outputs on the second card mirror
instead of extending the desktop, unlike the secondary port on the first card
(in TW):
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 16384 x 16384
HDMI-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis)
700mm x 390mm
DVI-I-1-3 connected (normal left inverted right x axis y axis)
DVI-I-1-2 connected (normal left inverted right x axis y axis)
DVI-I-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y
axis) 519mm x 324mm
   1920x1200     59.95*+
   1920x1080     60.00*+  60.00    50.00    59.94    59.93
# xrandr --auto
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
Screen 0: minimum 320 x 200, current 3840 x 1440, maximum 16384 x 16384
HDMI-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis)
700mm x 390mm
DVI-I-1-3 connected 2560x1080+0+0 (normal left inverted right x axis y axis)
673mm x 284mm
DVI-I-1-2 connected 2560x1440+0+0 (normal left inverted right x axis y axis)
598mm x 336mm
DVI-I-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y
axis) 519mm x 324mm
   2560x1440     59.95*+
   2560x1080     60.00*+
   1920x1200     59.95*+
   1920x1080     60.00*+  60.00    50.00    59.94    59.93

Dropping back to using 1 connected output on secondary card works the same as
with 2.

An xrandr startup script lays things out nicely:
# xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x43; cap: 0xf (Source Output, Sink Output, Source Offload,
Sink Offload); crtcs: 2; outputs: 3; associated providers: 1; name: modesetting
    output DVI-I-1
    output HDMI-1
    output VGA-1
Provider 1: id: 0xef; cap: 0xf (Source Output, Sink Output, Source Offload,
Sink Offload); crtcs: 2; outputs: 2; associated providers: 1; name: modesetting
    output DVI-I-1-2
    output DVI-I-1-3
# grep -v ^\# /etc/X11/xinit/xinitrc.d/setup | grep xrandr
xrandr --dpi 120
xrandr --auto
xrandr --dpi 120 --output DVI-I-1 --mode 1920x1200 --primary --below DVI-I-1-2
--output HDMI-1 --mode 1920x1080 --right-of DVI-I-1 --output DVI-I-1-2 --mode
2560x1080
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
Screen 0: minimum 320 x 200, current 3840 x 2280, maximum 16384 x 16384
HDMI-1 connected 1920x1080+1920+1080 (normal left inverted right x axis y axis)
700mm x 390mm
DVI-I-1-2 connected 2560x1080+0+0 (normal left inverted right x axis y axis)
673mm x 284mm
DVI-I-1 connected primary 1920x1200+0+1080 (normal left inverted right x axis y
axis) 519mm x 324mm
   2560x1080     60.00*+
   1920x1200     59.95*+
   1920x1080     60.00*+  60.00    50.00    59.94    59.93
#

When I put only xrandr --auto in the startup script, the second card's display
remains a mirror:
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 16384 x 16384
HDMI-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis)
700mm x 390mm
DVI-I-1-2 connected 2560x1080+0+0 (normal left inverted right x axis y axis)
673mm x 284mm
DVI-I-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y
axis) 519mm x 324mm
   2560x1080     60.00*+
   1920x1200     59.95*+
   1920x1080     60.00*+  60.00    50.00    59.94    59.93

This works as expected too:
# grep -v ^\# /etc/X11/xinit/xinitrc.d/setup | grep xrandr
xrandr --dpi 120
xrandr --auto
xrandr --output DVI-I-1 --primary --output HDMI-1 --right-of DVI-I-1-2 --output
DVI-I-1-2 --right-of DVI-I-1
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
Screen 0: minimum 320 x 200, current 6400 x 1200, maximum 16384 x 16384
HDMI-1 connected 1920x1080+4480+0 (normal left inverted right x axis y axis)
700mm x 390mm
DVI-I-1-2 connected 2560x1080+1920+0 (normal left inverted right x axis y axis)
673mm x 284mm
DVI-I-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y
axis) 519mm x 324mm
   2560x1080     60.00*+
   1920x1200     59.95*+
   1920x1080     60.00*+  60.00    50.00    59.94    59.93

So, outputs do work as expected in TW by using xrandr --auto, but automagic
remains regressed, mixing desktop extension with mirroring. :P