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What exactly does the settings window of Ubuntu 24.04 show as it title when the Displays section is open?

I opened the Settings and went to the Displays section, because the resolution of my second monitor had changed since the last boot. The strange thing is that the window title was "christmann informationstechnik + medien GmbH & Co. KG CH7218" as you can see in this screenshot:

screenshot

Usually the title changes from "Displays" to some description of the monitor once you select one, so for me it should be "LG Electronics 27"". I tried to get some more information by running: ls /sys/class/drm/*/edid | xargs -i{} sh -c "echo {}; parse-edid < {}" (from this question) and got the following output

/sys/class/drm/card1-DP-1/edid
/sys/class/drm/card1-DP-2/edid
Section "Monitor"
    Identifier "CH7218"
    ModelName "CH7218"
    VendorName "CHR"
    # Monitor Manufactured week 9 of 2012
    # EDID version 1.4
    # Digital Display
    DisplaySize 1600 900
    Gamma 2.20
    Option "DPMS" "true"
    Horizsync 13-46
    VertRefresh 23-61
    # Maximum pixel clock is 150MHz

#Extension block found. Parsing...



extb[4]: 0x23 (0x20)
/sys/class/drm/card1-DP-3/edid
Section "Monitor"
    Identifier "LG HDR 4K"
    ModelName "LG HDR 4K"
    VendorName "GSM"
    # Monitor Manufactured week 12 of 2020
    # EDID version 1.3
    # Digital Display
    DisplaySize 600 340
    Gamma 2.20
    Option "DPMS" "true"
    Horizsync 30-135
    VertRefresh 48-61
    # Maximum pixel clock is 600MHz
    #Not giving standard mode: 1152x864, 60Hz
    #Not giving standard mode: 1280x1024, 60Hz
    #Not giving standard mode: 1280x720, 60Hz
    #Not giving standard mode: 1600x900, 60Hz
    #Not giving standard mode: 1920x1080, 60Hz
    #Not giving standard mode: 1280x800, 60Hz


#Extension block found. Parsing...



#WARNING: I may have missed a mode (CEA mode 97)
#WARNING: I may have missed a mode (CEA mode 96)
#WARNING: I may have missed a mode (CEA mode 93)
#WARNING: I may have missed a mode (CEA mode 94)
#WARNING: I may have missed a mode (CEA mode 95)
    Modeline    "Mode 10" +hsync +vsync 
    Modeline    "Mode 0" +hsync +vsync 
    Modeline    "Mode 1" +hsync -vsync 
    Modeline    "Mode 2" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
    Modeline    "Mode 3" 74.250 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
    Modeline    "Mode 4" 74.250 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
    Modeline    "Mode 5" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
    Modeline    "Mode 6" 27.000 720 732 796 864 576 581 586 625 -hsync -vsync
    Modeline    "Mode 7" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
    Modeline    "Mode 8" 74.250 1280 1390 1420 1650 720 725 730 750 +hsync +vsync
    Modeline    "Mode 9" 25.200 640 656 752 800 480 490 492 525 -hsync -vsync
    Modeline    "Mode 11" +hsync -vsync 
    Option "PreferredMode" "Mode 10"
EndSection
/sys/class/drm/card1-HDMI-A-1/edid
/sys/class/drm/card1-Writeback-1/edid

Both monitors are the same model and are connected via a DisplayPort to HDMI converter cable. But neither "LG Electronics 27"" nor the company name appear in the edid info. CH7218 seems to be a DisplayPort to HDMI converter (manufacturer page) so that kind of makes sense to me. Maybe it just reports CH7218 if the HDMI handshake fails or something.

But where does the company name come from and why is it displayed as window title?

The company does exist but I could not find any connection to DisplayPort cables or such. (company page)

Unfortunately I did not have time to dig much deeper when this happened and had to turn off the machine. The problem was gone when I turned it back on. Parse-edid now shows the same info for both monitors (same as for /sys/class/drm/card1-DP-3/edid from above). And everything seems to work normal.

Thanks for any hints what might have happened or how I can investigate further if this happens again.

user2112637
  • 1

0 Answers0