Sudden Problem Using Two Monitors in 'Join Displays' mode

Nanki_Poo · 11-04-2022, 10:40 AM

Good afternoon everyone. I have been using my desktop setup with several flavours of Linux over the last two years, always with dual monitors joined together under the 'Join Displays' option in settings.

My latest Debian installation decided to crash and burn, so I had to reinstall. I initially installed latest Mint (the only USB I had available), and as soon as it loaded the login screen, the displays went wrong, mixing the images for each display on the primary monitor, and scrambled pixels on the secondary ( See this picture http://grayzone.co.uk/screens_crop.jpg ). I then went ahead and started my Debian installation, and the same thing happened after install was finished.

Strangely, it WILL allow me to mirror the screens. If I do this or use a single screen, if I then click back on the 'Join Displays' tab, the 'Apply' button is greyed out.

I can't seem to find this problem anywhere, and wondered if anyone has experienced this and resolved it, please?

System details:
Debian 11 Buster
Graphics: AMD Radeon X800
Motherboard: ROG STRIX B450-F
Processor: AMD Ryzen 5 3600
Screens: Dell 24" / V7 L22WD

Thanks in advance for any help.

business_kid · 11-05-2022, 08:29 AM

You can do that with settings in /etc/X11/xorg.conf.d/

The usual thing is to write and add something like 20-video conf. 'Man xorg.conf' is your friend, under the Display section. If you look at the man page there are/used to be some settings

Virtual # sets the size of the X display. So for 2 hdmi screens, virtual 3840 2160 or suchlike.
Position # tells X what position the top left dot of this screen goes in.

Have a read for yourself, and be glad you're not back in the days when you'd write your own modeline, and then adjust it to get all the picture visible.

mrmazda · 11-05-2022, 09:36 PM

Your motherboard has DisplayPort and HDMI port available for use with an AMD processor providing graphics, unlike your current processor. Any of these supported processors would provide superior performance to an ancient X800 ATI PCIe graphics card.

If you must keep the X800, it should work automagically with a total of two displays. It's the same ATI generation as my X600, which works with Debian 11 automagically:

Code:

# xdriinfo
Screen 0: r300
# inxi -GSaz --vs
inxi 3.3.23-00 (2022-10-31)
System:
  Kernel: 5.19.0-0.deb11.2-amd64 arch: x86_64 bits: 64 compiler: gcc v: 10.2.1
    parameters: BOOT_IMAGE=/vmlinuz root=LABEL=<filter> noresume
    ipv6.disable=1 net.ifnames=0 mitigations=auto
  Desktop: Trinity v: R14.0.13 tk: Qt v: 3.5.0 info: kicker wm: Twin v: 3.0
    vt: 7 dm: 1: TDM 2: XDM Distro: Debian GNU/Linux 11 (bullseye)
Graphics:
  Device-1: AMD RV380 [Radeon X550/X600] vendor: Micro-Star MSI driver: radeon
    v: kernel alternate: radeonfb,amdgpu arch: Rage-9 code: R360-R400
    process: TSMC 110nm built: 2003-08 pcie: gen: 1 speed: 2.5 GT/s lanes: 16
    ports: active: DVI-I-1,VGA-1 empty: SVIDEO-1 bus-ID: 01:00.0
    chip-ID: 1002:3e50 class-ID: 0300
  Display: x11 server: X.Org v: 1.20.11 driver: X: loaded: radeon
    unloaded: fbdev,modesetting,vesa dri: r300 gpu: radeon display-ID: :0
    screens: 1
  Screen-1: 0 s-res: 3600x1200 s-dpi: 120 s-size: 762x254mm (30.00x10.00")
    s-diag: 803mm (31.62")
  Monitor-1: DVI-I-1 mapped: DVI-0 pos: primary,left model: NEC EA243WM
    serial: <filter> built: 2011 res: 1920x1200 hz: 60 dpi: 94 gamma: 1.2
    size: 519x324mm (20.43x12.76") diag: 612mm (24.1") ratio: 16:10 modes:
    max: 1920x1200 min: 640x480
  Monitor-2: VGA-1 mapped: VGA-0 pos: right model: Dell P2213
    serial: <filter> built: 2012 res: 1680x1050 hz: 60 dpi: 90 gamma: 1.2
    size: 473x296mm (18.62x11.65") diag: 558mm (22") ratio: 16:10 modes:
    max: 1680x1050 min: 720x400
  API: OpenGL v: 2.1 Mesa 20.3.5 renderer: ATI RV380 direct render: Yes
#

Possibly your X800 doesn't have enough VRAM to support both displays at full resolution.

Please remove /etc/inxi.conf, then run sudo inxi -U, then provide output here from an X session from the following run in an X terminal:

Code:

xdriinfo
inxi -GSaz --vs