Public bug reported:
text
i915/nvidia-drm falla al conectar hub USB-C — pantalla externa queda en
gris
Description:
When connecting a USB-C hub (Wowssyo 4-in-1) with an HDMI monitor (LG
72") to an MSI Thin 15 B13VE laptop, the external display is detected by
the system but cannot be activated. The display appears as "connected"
but shows as gray/disabled in display settings, and cannot be turned on.
The Samsung monitor connected directly via the laptop's HDMI port works
fine.
System: Ubuntu 26.04 (or current), GNOME 50 / Mutter 50, Xfce (Xorg), Kernel
7.0.0-38-generic
Hardware: MSI Thin 15 B13VE
- Intel Raptor Lake-P UHD (i915)
- NVIDIA RTX 4050 Laptop (nvidia-drm)
- /dev/dri/card0 → NVIDIA
- /dev/dri/card1 → Intel
Hub: Wowssyo 4-in-1 USB-C hub
Monitors involved:
- Samsung (via direct HDMI) → WORKS
- LG Electronics 72" (via hub USB-C → HDMI) → FAILS
Steps to reproduce:
1. Boot into Ubuntu (any desktop session, both GNOME/Wayland and Xfce/Xorg
affected).
2. Connect the USB-C hub.
3. Connect the LG monitor via HDMI to the hub.
4. Open the display settings and try to enable the LG monitor.
5. The LG appears as "connected" but cannot be enabled — it stays gray/disabled.
Expected behavior:
The LG monitor should activate and display the desktop normally.
Actual behavior:
- The LG monitor is detected but cannot be enabled.
- It appears gray/disabled in the display configuration tool.
- In Xfce/Xorg: the display stays gray, no crash but the monitor is unusable.
- In GNOME/Wayland: GNOME Shell crashes with SIGABRT (signal 6), the session
restarts, and screens go black.
Relevant kernel log evidence:
oct 08 00:58:14 alejandro-Thin-15-B13VE kernel:
[drm:nv_drm_dumb_map_offset [nvidia_drm]] *ERROR* [nvidia-drm] [GPU ID
0x00000100] Failed to lookup gem object for mapping: 0x00000007
oct 08 01:00:40 alejandro-Thin-15-B13VE kernel: [drm:nv_drm_dumb_map_offset
[nvidia_drm]] *ERROR* [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem
object for mapping: 0x00000006
oct 08 01:00:40 alejandro-Thin-15-B13VE kernel: [drm:nv_drm_dumb_map_offset
[nvidia_drm]] *ERROR* [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem
object for mapping: 0x00000007
The error appears in nvidia-drm when trying to map a GEM object during
the display activation attempt via the USB-C hub. This strongly suggests
a failure in the coordination between the i915 (Intel) and nvidia-drm
(NVIDIA) drivers when a DisplayPort Alt Mode link is established through
the USB-C hub.
Additional info:
- The Samsung monitor connected directly via the laptop's HDMI port works
without issues.
- Both GNOME (Wayland) and Xfce (Xorg) are affected, but the symptoms differ:
GNOME Shell crashes, Xfce just cannot enable the display.
- The issue is reproducible with kernels 7.0.0-34-generic and 7.0.0-38-generic.
- NVIDIA driver: 595.91.07
- nvidia_drm modeset: Y
- nvidia_drm fbdev: Y
I suspect the issue is related to how DisplayPort Alt Mode over USB-C is
handled when multiple GPUs are present. Please let me know what
additional logs or tests would help diagnose this
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-38-generic 7.0.0-38.38
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: alejandro 3233 F.... pipewire
alejandro 3244 F.... wireplumber
/dev/snd/controlC0: alejandro 3244 F.... wireplumber
/dev/snd/seq: alejandro 3233 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: XFCE
Date: Thu Oct 8 01:33:34 2026
InstallationDate: Installed on 2025-11-06 (336 days ago)
InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64
(20250805.1)
MachineType: Micro-Star International Co., Ltd. Thin 15 B13VE
ProcEnviron:
LANG=es_ES.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
ProcFB:
0 i915drmfb
1 nvidia-drmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic
root=UUID=3b440898-feb7-4a6a-b11d-0eec6081809d ro quiet splash
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
SourcePackage: linux
UpgradeStatus: Upgraded to resolute on 2026-10-05 (3 days ago)
dmi.bios.date: 04/07/2026
dmi.bios.release: 7.13
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: E16R8IMS.70D
dmi.board.asset.tag: Default string
dmi.board.name: MS-16R8
dmi.board.vendor: Micro-Star International Co., Ltd.
dmi.board.version: REV:1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Micro-Star International Co., Ltd.
dmi.chassis.version: N/A
dmi.modalias:
dmi:bvnAmericanMegatrendsInternational,LLC.:bvrE16R8IMS.70D:bd04/07/2026:br7.13:svnMicro-StarInternationalCo.,Ltd.:pnThin15B13VE:pvrREV1.0:rvnMicro-StarInternationalCo.,Ltd.:rnMS-16R8:rvrREV1.0:cvnMicro-StarInternationalCo.,Ltd.:ct10:cvrN/A:sku16R8.7:pfaThin:
dmi.product.family: Thin
dmi.product.name: Thin 15 B13VE
dmi.product.sku: 16R8.7
dmi.product.version: REV:1.0
dmi.sys.vendor: Micro-Star International Co., Ltd.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute
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https://bugs.launchpad.net/bugs/2169940
Title:
text Fallo de coordinación i915/nvidia-drm al conectar hub USB-C:
pantalla queda en gris (nv_drm_dumb_map_offset)
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