Re: Problems with dual displays
Clement @ Leitersburg Lawn and Garden LLC composed on 2025-11-20 06:54 (UTC-0500):
> Felix Miata wrote:
>> Charles Curley composed on 2025-11-19 13:21 (UTC-0700):
>>> On Wed, 19 Nov 2025 13:48:47 -0500 "Clement @ Leitersburg Lawn and Garden LLC" wrote:
>>>> I upgraded to Trixie this morning and had a problem with my dual monitors.
>>>> Only the one connected with the VGA cable was recognized even after a restart.
>>>> The other monitor is connected with a DVI cable. Even after switching
>>>> cables, only the monitor connected via the VGA cable worked.
>>> Rather than fiddle with different kernels, let's solve the DVI monitor problem.
>>> You didn't say what you are using as a desktop/window manager, nor what
>>> video card you are using.
>> Show us what you have and how it's setup using:
>> inxi -GSaz --za
> System:
> Kernel: 6.1.0-40-amd64 arch: x86_64 bits: 64 compiler: gcc v: 12.2.0
> clocksource: tsc avail: hpet,acpi_pm
> parameters: BOOT_IMAGE=/boot/vmlinuz-6.1.0-40-amd64 root=UUID=<filter> ro
> quiet
> Desktop: GNOME v: 48.4 tk: GTK v: 3.24.49 wm: gnome-shell
> tools: gsd-screensaver-proxy avail: gnome-screensaver, light-locker,
> lxlock, xscreensaver dm: 1: LightDM v: 1.32.0 2: SDDM note: stopped
> Distro: Debian GNU/Linux 13 (trixie)
> Graphics:
> Device-1: Intel CometLake-S GT2 [UHD Graphics 630] vendor: Gigabyte
> driver: i915 v: kernel arch: Gen-9.5 process: Intel 14nm built: 2016-20
> ports: active: DP-1,HDMI-A-1 empty: HDMI-A-2 bus-ID: 00:02.0
> chip-ID: 8086:9bc5 class-ID: 0300
> Display: x11 server: X.Org v: 21.1.16 with: Xwayland v: 24.1.6
> compositor: gnome-shell driver: X: loaded: modesetting unloaded: fbdev,vesa
> dri: iris gpu: i915 display-ID: :0 screens: 1
> Screen-1: 0 s-res: 3840x1080 s-dpi: 96 s-size: 1016x285mm (40.00x11.22")
> s-diag: 1055mm (41.54")
> Monitor-1: DP-1 pos: left model: Dell P2214H serial: <filter> built: 2015
> res: mode: 1920x1080 hz: 60 scale: 100% (1) dpi: 102 gamma: 1.2
> size: 477x268mm (18.78x10.55") diag: 547mm (21.5") ratio: 16:9 modes:
> max: 1920x1080 min: 720x400
> Monitor-2: HDMI-A-1 mapped: HDMI-1 pos: primary,right model: Dell P2214H
> serial: <filter> built: 2015 res: mode: 1920x1080 hz: 60 scale: 100% (1)
> dpi: 102 gamma: 1.2 size: 477x268mm (18.78x10.55") diag: 547mm (21.5")
> ratio: 16:9 modes: max: 1920x1080 min: 720x400
> API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris
> device: 1 drv: swrast gbm: drv: iris surfaceless: drv: iris x11: drv: iris
> inactive: wayland
> API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa v: 25.0.7-2 glx-v: 1.4
> direct-render: yes renderer: Mesa Intel UHD Graphics 630 (CML GT2)
> device-ID: 8086:9bc5 memory: 38.28 GiB unified: yes
> API: Vulkan v: 1.4.309 layers: 4 device: 0 type: integrated-gpu name: Intel
> UHD Graphics 630 (CML GT2) driver: mesa intel v: 25.0.7-2
> device-ID: 8086:9bc5 surfaces: xcb,xlib device: 1 type: cpu name: llvmpipe
> (LLVM 19.1.7 256 bits) driver: mesa llvmpipe v: 25.0.7-2 (LLVM 19.1.7)
> device-ID: 10005:0000 surfaces: xcb,xlib
> Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo de: kscreen-console,
> kscreen-doctor, xfce4-display-settings gpu: nvidia-settings,nvidia-smi
> wl: wayland-info,wdisplays x11: xdriinfo, xdpyinfo, xprop, xrandr
Debian 12 Bookworm's inxi is old and broken, so the above report misleading.
Please upgrade inxi and then submit the report again, but not yet. It also shows
you are running Debian 13 Trixie using a Debian 12 Bookworm kernel. This strongly
suggests an incomplete upgrade that needs to be completed before proper display
behavior can be expected. Current Trixie kernel is 6.12, not 6.1.
Your OP noted use of VGA and DVI cables connected to the displays, but the inxi
report only lists DisplayPort and HDMI outputs. This is common on newer models of
Intel GPUs, but usually dealt with adequately with newer inxi versions. These GPUs
only provide DP and HDMI ports, but motherboards often use converters that provide
DVI and/or VGA output connectors to support older displays. For those that do not,
there are external converters that do the same thing. You should tell us whether
or not you are using external connectors, to clarify whether this may play a part
in your issue. Trixie's inxi 3.3.38 should be new enough for a proper report.
The report indicates P2214 displays. I have 3 P2213 Dells. Mine have DisplayPort,
DVI and VGA inputs, so I suspect yours do too. If I'm right about this, and my
suspicion about your motherboard's outputs, you should do well to stop using the
VGA cable and use a DisplayPort cable instead. VGA usage means multiple
conversions in the path between display screen and GPU. VGA outputs on modern
hardware are there to facilitate use of very old displays when necessary, mostly
CRT screens, which does not appear to be your case.
Before going further with this thread, you should finish your upgrade to Trixie,
and if you need help, start a new thread.
--
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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