Re: Activate additional monitor
Van Snyder composed on 2025-07-21 12:35 (UTC-0700):
> I have a desktop system with HDMI graphics on the motherboard and a
> graphics card. Here's the output from inxi -G:
> Device-1: Intel Raptor Lake-S GT1 [UHD Graphics 770] driver: i915 v:
> kernel
> Device-2: NVIDIA GM107GL [Quadro K2200] driver: nouveau v: kernel
For troubleshooting purposes, inxi -G with no other options is little short
of useless. With graphics issues, best to provide inxi -GSaz --vs. Bookworm's
inxi is broken, so should be upgraded from upstream using the -U switch as
superuser after unblocking the -U switch in /etc/inxi.conf, or by upgrading
the Debian inxi package to the backports version. e.g.:
# inxi -GSaz --vs --za --hostname
inxi 3.3.38-00 (2025-04-06)
System:
Host: gb970 Kernel: 6.1.0-37-amd64 arch: x86_64 bits: 64 compiler: gcc
v: 12.2.0 clocksource: tsc avail: hpet,acpi_pm
parameters: root=LABEL=<filter> ipv6.disable=1 net.ifnames=0
plymouth.enable=0 noresume consoleblank=0 mitigations=off
Desktop: TDE (Trinity) v: R14.1.4 tk: Qt v: 3.5.0 wm: Twin v: 3.0
with: kicker vt: 7 dm: 1: TDM 2: XDM Distro: Debian GNU/Linux 12 (bookworm)
Graphics:
Device-1: NVIDIA GM107GL [Quadro K2200] vendor: Hewlett-Packard
driver: nouveau v: kernel non-free: 550-570.xx+ status: current (as of
2025-04; EOL~2026-12-xx) arch: Maxwell code: GMxxx process: TSMC 28nm
built: 2014-2019 pcie: gen: 2 speed: 5 GT/s lanes: 16 link-max: gen: 3
speed: 8 GT/s ports: active: DP-1,DP-2,DVI-I-1 empty: none bus-ID: 01:00.0
chip-ID: 10de:13ba class-ID: 0300 temp: 51.0 C
Display: x11 server: X.Org v: 1.21.1.7 compositor: Twin v: 3.0 driver: X:
loaded: modesetting unloaded: fbdev,vesa dri: nouveau gpu: nouveau
display-ID: :0 screens: 1
Screen-1: 0 s-res: 3600x2640 s-dpi: 120 s-size: 762x558mm (30.00x21.97")
s-diag: 944mm (37.18")
Monitor-1: DP-1 pos: primary,bottom-l model: Acer K272HUL serial: <filter>
built: 2018 res: mode: 2560x1440 hz: 60 scale: 100% (1) dpi: 109 gamma: 1.2
size: 598x336mm (23.54x13.23") diag: 686mm (27") ratio: 16:9 modes:
max: 2560x1440 min: 720x400
Monitor-2: DP-2 pos: top-left model: NEC EA243WM serial: <filter>
built: 2011 res: mode: 1920x1200 hz: 60 scale: 100% (1) dpi: 94 gamma: 1.2
size: 519x324mm (20.43x12.76") diag: 612mm (24.1") ratio: 16:10 modes:
max: 1920x1200 min: 640x480
Monitor-3: DVI-I-1 pos: top-right model: Dell P2213 serial: <filter>
built: 2013 res: mode: 1680x1050 hz: 60 scale: 100% (1) dpi: 90 gamma: 1.2
size: 473x296mm (18.62x11.65") diag: 558mm (22") ratio: 16:10 modes:
max: 1680x1050 min: 720x400
API: EGL v: 1.5 hw: drv: nvidia nouveau platforms: device: 0 drv: nouveau
device: 1 drv: swrast gbm: drv: nouveau surfaceless: drv: nouveau x11:
drv: nouveau inactive: wayland
API: OpenGL v: 4.3 vendor: nouveau mesa v: 22.3.6 glx-v: 1.4 es-v: 3.2
direct-render: yes renderer: NV117 device-ID: 10de:13ba memory: 3.86 GiB
unified: no
API: Vulkan v: 1.3.239 layers: 4 device: 0 type: cpu name: llvmpipe (LLVM
15.0.6 128 bits) driver: mesa llvmpipe v: 22.3.6 (LLVM 15.0.6)
device-ID: 10005:0000 surfaces: xcb,xlib
Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo x11: xdriinfo,
xdpyinfo, xprop, xrandr
#
> It's running Debian 12.11 with kernel 6.1.140-1.
> If I connect the HDMI monitor before boot, it works. If I connect the
> HDMI monitor after the system is running, it doesn't work.
> Is there a magic incantation that can be used after boot to find and
> connect the HDMI monitor?
# ls -gGh /sys/class/drm
total 0
lrwxrwxrwx 1 0 Jul 22 23:39 card0 -> ../../devices/pci0000:00/0000:00:02.0/0000:01:00.0/drm/card0
lrwxrwxrwx 1 0 Jul 22 23:39 card0-DP-1 -> ../../devices/pci0000:00/0000:00:02.0/0000:01:00.0/drm/card0/card0-DP-1
lrwxrwxrwx 1 0 Jul 22 23:39 card0-DP-2 -> ../../devices/pci0000:00/0000:00:02.0/0000:01:00.0/drm/card0/card0-DP-2
lrwxrwxrwx 1 0 Jul 22 23:39 card0-DVI-I-1 -> ../../devices/pci0000:00/0000:00:02.0/0000:01:00.0/drm/card0/card0-DVI-I-1
lrwxrwxrwx 1 0 Jul 22 23:39 renderD128 -> ../../devices/pci0000:00/0000:00:02.0/0000:01:00.0/drm/renderD128
-r--r--r-- 1 4.0K Jul 22 23:48 version
#
What you see above are kernel names for the connectors found. It is often
the case that kernel names and X names will differ. When this occurs, inxi
calls it mapping, e.g.:
Monitor-1: HDMI-A-2 mapped: HDMI-2 model: Samsung SMS24A850 res: 1920x1200
hz: 60 dpi: 94 diag: 611mm (24.1")
> Or is there a kernel parameter I can put into /etc/default/grub?
Have you visited the BIOS while both these GPUs are present in the system?
GPU configuration there may need some tweaking. Which graphics outputs are
you connecting your video cables to, NVidia card, motherboard, or both (non-
broken inxi -GSaz should show this)?
Sometimes a kernel cmdline option video= can be useful.
<https://www.kernel.org/doc/Documentation/fb/modedb.txt> explains the video=
options. e.g., to force the monitor on DP-3 to always be enabled @2560x1440
with 60 refresh, use:
video=DP-3:2560x1440@60e
Normally though, video= only works for the vttys. IOW, X does its own thing.
Sometimes, not often IME, X will take the hint from a video= parameter.
--
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
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