Public bug reported:
Since upgrading from Ubuntu 24.04.5 to 26.04.1 (do-release-upgrade), two
external DisplayPort monitors connected through a ThinkPad Thunderbolt 3
Dock no longer work with nouveau on kernel 7.0.0-38-generic: they show
no signal (case 1).
Booting 7.0.0-38-generic with nouveau.config=NvGspRm=0, the external
monitors activate and show the boot splash, but Plasma never finishes
starting (case 2). Also setting NOUVEAU_USE_ZINK=0 in the session
environment allows Plasma to start fully, but with rendering corruption
on the external monitors (cases 3 and 4).
The same hardware works fine on 6.8.0-147-generic (still installed from
24.04) with the same 26.04.1 userspace without any custom kernel command
line options or environment variables (case 5).
The corruption in cases 3 and 4 is a separate issue: it also occurs on
6.8.0-147 with NOUVEAU_USE_ZINK=0 set (case 6), and stops once the
variable is removed (case 7).
== Expected ==
Both external monitors display output through the dock on
7.0.0-38-generic with default options, as they do on 6.8.0-147-generic.
== Actual ==
Both external monitors show no signal on 7.0.0-38-generic with default
options. See Results for behaviour with nouveau.config=NvGspRm=0 and
NOUVEAU_USE_ZINK=0.
== Hardware ==
- Laptop: Lenovo ThinkPad P15 Gen 1 (20ST0055AU), BIOS N30ET62W (1.98) dated
24/03/2026
- iGPU: Intel CometLake-H GT2 [UHD Graphics] [8086:9bc4] (rev 05), i915, drives
eDP
- dGPU: NVIDIA TU117GLM [Quadro T1000 Mobile] [10de:1fb9] (rev a1), nouveau,
VBIOS 90.17.41.00.3f
- Dock: Lenovo ThinkPad Thunderbolt 3 Dock (USB 17ef:3082), connected via
USB-C/Thunderbolt
- Monitors: 2x HP E24 G4, 1920x1080@60, DisplayPort from the dock
- The external monitors appear as DP connectors on the nouveau DRM device.
== Software ==
- Ubuntu 26.04.1 LTS
- linux-image-7.0.0-38-generic 7.0.0-38.38 (affected)
- linux-image-6.8.0-147-generic 6.8.0-147.147 (works)
- linux-firmware 20260319.git217ca6e4.1ubuntu (GSP firmware present:
nvidia/tu117/gsp/gsp-570.144.bin.zst)
- libgl1-mesa-dri / mesa-vulkan-drivers 26.0.8-1ubuntu0.3
- libdrm2 2.4.131-1
- kwin-wayland / plasma-workspace 6.6.6 (Plasma Wayland session)
- No nouveau options in /etc/modprobe.d. Base kernel cmdline: "ro quiet splash"
== Results ==
1. 7.0.0-38, default options
- Kernel log: "nouveau 0000:01:00.0: gsp: RM version: 570.144"
- Both monitors report no input and stay black.
- Both DP connectors: status=connected, enabled=enabled, dpms=On.
- KDE display settings detect both monitors and treat them as active
(windows are placed on them).
- KWin log: "drmSetClientCap for Atomic Mode Setting failed. Using legacy
mode on GPU" (nouveau device).
- No "job timeout" messages in the kernel log.
- Log: boot-7.0-gsp-on-black.log
2. 7.0.0-38, nouveau.config=NvGspRm=0
- No GSP RM version line; kernel log shows "pmu: firmware unavailable".
- Boot splash appears on both external monitors.
- Plasma never finishes starting. External keyboard numlock and
Ctrl+Alt+F3/F4 don't respond.
A short power key press is logged by systemd-logind and shutdown proceeds.
- Kernel and KWin log:
nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 4 killed!
nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 2 killed!
kwin_scene_opengl: 0x1: GL_INVALID_OPERATION in
glBindFramebuffer(non-gen name)
kwin_scene_opengl: 0x1: GL_INVALID_FRAMEBUFFER_OPERATION in
glClear(incomplete framebuffer)
MESA: error: ZINK: vkQueueSubmit failed (VK_ERROR_DEVICE_LOST)
followed by plasma-ksplash.service and plasma-kcminit.service start
timeouts.
- Log: boot-7.0-gsp-off-hang.log
3. 7.0.0-38, nouveau.config=NvGspRm=0, plus NOUVEAU_USE_ZINK=0 in
~/.config/environment.d/
- Plasma starts and both external monitors display output.
- Rendering corruption on the external monitors: while typing in a terminal
window, parts of
the text appear and disappear. Moving the window renders it correctly
until the next keystroke.
- KWin still logs legacy mode on the nouveau device, and the same
GL_INVALID_OPERATION /
GL_INVALID_FRAMEBUFFER_OPERATION messages at startup (these also appear on
6.8.0-147, see case 7).
- In this boot, KWIN_DRM_FORCE_MGPU_GL_FINISH=1 and then also
KWIN_USE_BUFFER_AGE=0 were set
(confirmed in the systemd user environment, applied by logging out and
in). No change in either case.
- Log: boot-7.0-gsp-off-zink-off-corruption.log
4. As case 3, plus nouveau.atomic=1
- KWin no longer logs legacy mode; the startup GL errors are no longer
logged.
- KWin logs "kwin_wayland_drm: The main thread was hanging temporarily!"
during startup.
- Corruption on the external monitors is unchanged.
- Log: boot-7.0-gsp-off-zink-off-atomic-corruption.log
5. 6.8.0-147-generic, default options, no environment overrides
- No GSP line in kernel log ("pmu: firmware unavailable").
- Both external monitors work through the dock, no corruption observed.
- Log: boot-6.8-working-kernel.log (kernel messages only)
6. 6.8.0-147-generic, default options, NOUVEAU_USE_ZINK=0 in
~/.config/environment.d/
- Same corruption as cases 3 and 4: typed text in a terminal on the external
monitors appears and
disappears; moving the window renders it correctly until the next
keystroke.
- Log: boot-6.8-zink-off-corruption.log (first session in this boot)
7. 6.8.0-147-generic, NOUVEAU_USE_ZINK=0 removed, logged out and back in (same
boot as case 6)
- Corruption no longer occurs.
- KWin logs the GL_INVALID_OPERATION / GL_INVALID_FRAMEBUFFER_OPERATION
messages at startup in
both the case 6 and case 7 sessions.
- Log: boot-6.8-zink-off-corruption.log (second session in this boot)
== Attachments ==
Journal extracts for each boot above, plus the requested system information:
- boot-7.0-gsp-on-black.log
- boot-7.0-gsp-off-hang.log
- boot-7.0-gsp-off-zink-off-corruption.log
- boot-7.0-gsp-off-zink-off-atomic-corruption.log
- boot-6.8-working-kernel.log
- boot-6.8-zink-off-corruption.log
- version.log (cat /proc/version_signature, booted into 7.0.0-38-generic)
- lspci-vnvn.log (sudo lspci -vnvn, Device Serial Number lines redacted)
- lsb_release.log (lsb_release -rd)
- apt-cache-policy.log (apt-cache policy for the kernel, firmware, Mesa, libdrm
and KWin packages)
The logs are filtered to kernel, KWin, plasmashell, systemd-logind and
Plasma user service messages. Lines about networking, audit/AppArmor,
Secure Boot certificates, Bluetooth, storage encryption and unrelated
userspace crashes were removed. Hostname, username, MAC/IP addresses and
UUIDs were redacted. Unfiltered logs, or specific sections of them, are
available on request.
Happy to test patches, kernels or further options.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Description changed:
Since upgrading from Ubuntu 24.04.5 to 26.04.1 (do-release-upgrade), two
external DisplayPort monitors connected through a ThinkPad Thunderbolt 3
Dock no longer work with nouveau on kernel 7.0.0-38-generic: they show
no signal (case 1).
Booting 7.0.0-38-generic with nouveau.config=NvGspRm=0, the external
monitors activate and show the boot splash, but Plasma never finishes
starting (case 2). Also setting NOUVEAU_USE_ZINK=0 in the session
environment allows Plasma to start fully, but with rendering corruption
on the external monitors (cases 3 and 4).
The same hardware works fine on 6.8.0-147-generic (still installed from
24.04) with the same 26.04.1 userspace without any custom kernel command
line options or environment variables (case 5).
The corruption in cases 3 and 4 is a separate issue: it also occurs on
6.8.0-147 with NOUVEAU_USE_ZINK=0 set (case 6), and stops once the
variable is removed (case 7).
+
+ == Expected ==
+
+ Both external monitors display output through the dock on
+ 7.0.0-38-generic with default options, as they do on 6.8.0-147-generic.
+
+ == Actual ==
+
+ Both external monitors show no signal on 7.0.0-38-generic with default
+ options. See Results for behaviour with nouveau.config=NvGspRm=0 and
+ NOUVEAU_USE_ZINK=0.
== Hardware ==
- Laptop: Lenovo ThinkPad P15 Gen 1 (20ST0055AU), BIOS N30ET62W (1.98) dated
24/03/2026
- iGPU: Intel CometLake-H GT2 [UHD Graphics] [8086:9bc4] (rev 05), i915,
drives eDP
- dGPU: NVIDIA TU117GLM [Quadro T1000 Mobile] [10de:1fb9] (rev a1), nouveau,
VBIOS 90.17.41.00.3f
- Dock: Lenovo ThinkPad Thunderbolt 3 Dock (USB 17ef:3082), connected via
USB-C/Thunderbolt
- Monitors: 2x HP E24 G4, 1920x1080@60, DisplayPort from the dock
- The external monitors appear as DP connectors on the nouveau DRM device.
== Software ==
- Ubuntu 26.04.1 LTS
- linux-image-7.0.0-38-generic 7.0.0-38.38 (affected)
- linux-image-6.8.0-147-generic 6.8.0-147.147 (works)
- linux-firmware 20260319.git217ca6e4.1ubuntu (GSP firmware present:
nvidia/tu117/gsp/gsp-570.144.bin.zst)
- libgl1-mesa-dri / mesa-vulkan-drivers 26.0.8-1ubuntu0.3
- libdrm2 2.4.131-1
- kwin-wayland / plasma-workspace 6.6.6 (Plasma Wayland session)
- No nouveau options in /etc/modprobe.d. Base kernel cmdline: "ro quiet
splash"
== Results ==
1. 7.0.0-38, default options
- - Kernel log: "nouveau 0000:01:00.0: gsp: RM version: 570.144"
- - Both monitors report no input and stay black.
- - Both DP connectors: status=connected, enabled=enabled, dpms=On.
- - KDE display settings detect both monitors and treat them as active
(windows are placed on them).
- - KWin log: "drmSetClientCap for Atomic Mode Setting failed. Using legacy
mode on GPU" (nouveau device).
- - No "job timeout" messages in the kernel log.
- - Log: boot-7.0-gsp-on-black.log
+ - Kernel log: "nouveau 0000:01:00.0: gsp: RM version: 570.144"
+ - Both monitors report no input and stay black.
+ - Both DP connectors: status=connected, enabled=enabled, dpms=On.
+ - KDE display settings detect both monitors and treat them as active
(windows are placed on them).
+ - KWin log: "drmSetClientCap for Atomic Mode Setting failed. Using legacy
mode on GPU" (nouveau device).
+ - No "job timeout" messages in the kernel log.
+ - Log: boot-7.0-gsp-on-black.log
2. 7.0.0-38, nouveau.config=NvGspRm=0
- - No GSP RM version line; kernel log shows "pmu: firmware unavailable".
- - Boot splash appears on both external monitors.
- - Plasma never finishes starting. External keyboard numlock and
Ctrl+Alt+F3/F4 don't respond.
- A short power key press is logged by systemd-logind and shutdown
proceeds.
- - Kernel and KWin log:
- nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 4
killed!
- nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 2
killed!
- kwin_scene_opengl: 0x1: GL_INVALID_OPERATION in
glBindFramebuffer(non-gen name)
- kwin_scene_opengl: 0x1: GL_INVALID_FRAMEBUFFER_OPERATION in
glClear(incomplete framebuffer)
- MESA: error: ZINK: vkQueueSubmit failed (VK_ERROR_DEVICE_LOST)
- followed by plasma-ksplash.service and plasma-kcminit.service start
timeouts.
- - Log: boot-7.0-gsp-off-hang.log
+ - No GSP RM version line; kernel log shows "pmu: firmware unavailable".
+ - Boot splash appears on both external monitors.
+ - Plasma never finishes starting. External keyboard numlock and
Ctrl+Alt+F3/F4 don't respond.
+ A short power key press is logged by systemd-logind and shutdown
proceeds.
+ - Kernel and KWin log:
+ nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 4
killed!
+ nouveau 0000:01:00.0: kwin_wayland[3514]: job timeout, channel 2
killed!
+ kwin_scene_opengl: 0x1: GL_INVALID_OPERATION in
glBindFramebuffer(non-gen name)
+ kwin_scene_opengl: 0x1: GL_INVALID_FRAMEBUFFER_OPERATION in
glClear(incomplete framebuffer)
+ MESA: error: ZINK: vkQueueSubmit failed (VK_ERROR_DEVICE_LOST)
+ followed by plasma-ksplash.service and plasma-kcminit.service start
timeouts.
+ - Log: boot-7.0-gsp-off-hang.log
3. 7.0.0-38, nouveau.config=NvGspRm=0, plus NOUVEAU_USE_ZINK=0 in
~/.config/environment.d/
- - Plasma starts and both external monitors display output.
- - Rendering corruption on the external monitors: while typing in a
terminal window, parts of
- the text appear and disappear. Moving the window renders it correctly
until the next keystroke.
- - KWin still logs legacy mode on the nouveau device, and the same
GL_INVALID_OPERATION /
- GL_INVALID_FRAMEBUFFER_OPERATION messages at startup (these also appear
on 6.8.0-147, see case 7).
- - In this boot, KWIN_DRM_FORCE_MGPU_GL_FINISH=1 and then also
KWIN_USE_BUFFER_AGE=0 were set
- (confirmed in the systemd user environment, applied by logging out and
in). No change in either case.
- - Log: boot-7.0-gsp-off-zink-off-corruption.log
+ - Plasma starts and both external monitors display output.
+ - Rendering corruption on the external monitors: while typing in a
terminal window, parts of
+ the text appear and disappear. Moving the window renders it correctly
until the next keystroke.
+ - KWin still logs legacy mode on the nouveau device, and the same
GL_INVALID_OPERATION /
+ GL_INVALID_FRAMEBUFFER_OPERATION messages at startup (these also appear
on 6.8.0-147, see case 7).
+ - In this boot, KWIN_DRM_FORCE_MGPU_GL_FINISH=1 and then also
KWIN_USE_BUFFER_AGE=0 were set
+ (confirmed in the systemd user environment, applied by logging out and
in). No change in either case.
+ - Log: boot-7.0-gsp-off-zink-off-corruption.log
4. As case 3, plus nouveau.atomic=1
- - KWin no longer logs legacy mode; the startup GL errors are no longer
logged.
- - KWin logs "kwin_wayland_drm: The main thread was hanging temporarily!"
during startup.
- - Corruption on the external monitors is unchanged.
- - Log: boot-7.0-gsp-off-zink-off-atomic-corruption.log
+ - KWin no longer logs legacy mode; the startup GL errors are no longer
logged.
+ - KWin logs "kwin_wayland_drm: The main thread was hanging temporarily!"
during startup.
+ - Corruption on the external monitors is unchanged.
+ - Log: boot-7.0-gsp-off-zink-off-atomic-corruption.log
5. 6.8.0-147-generic, default options, no environment overrides
- - No GSP line in kernel log ("pmu: firmware unavailable").
- - Both external monitors work through the dock, no corruption observed.
- - Log: boot-6.8-working-kernel.log (kernel messages only)
+ - No GSP line in kernel log ("pmu: firmware unavailable").
+ - Both external monitors work through the dock, no corruption observed.
+ - Log: boot-6.8-working-kernel.log (kernel messages only)
6. 6.8.0-147-generic, default options, NOUVEAU_USE_ZINK=0 in
~/.config/environment.d/
- - Same corruption as cases 3 and 4: typed text in a terminal on the
external monitors appears and
- disappears; moving the window renders it correctly until the next
keystroke.
- - Log: boot-6.8-zink-off-corruption.log (first session in this boot)
+ - Same corruption as cases 3 and 4: typed text in a terminal on the
external monitors appears and
+ disappears; moving the window renders it correctly until the next
keystroke.
+ - Log: boot-6.8-zink-off-corruption.log (first session in this boot)
7. 6.8.0-147-generic, NOUVEAU_USE_ZINK=0 removed, logged out and back in
(same boot as case 6)
- - Corruption no longer occurs.
- - KWin logs the GL_INVALID_OPERATION / GL_INVALID_FRAMEBUFFER_OPERATION
messages at startup in
- both the case 6 and case 7 sessions.
- - Log: boot-6.8-zink-off-corruption.log (second session in this boot)
+ - Corruption no longer occurs.
+ - KWin logs the GL_INVALID_OPERATION / GL_INVALID_FRAMEBUFFER_OPERATION
messages at startup in
+ both the case 6 and case 7 sessions.
+ - Log: boot-6.8-zink-off-corruption.log (second session in this boot)
== Attachments ==
- Journal extracts for each boot above:
+ Journal extracts for each boot above, plus the requested system information:
- boot-7.0-gsp-on-black.log
- boot-7.0-gsp-off-hang.log
- boot-7.0-gsp-off-zink-off-corruption.log
- boot-7.0-gsp-off-zink-off-atomic-corruption.log
- boot-6.8-working-kernel.log
- boot-6.8-zink-off-corruption.log
+ - version.log (cat /proc/version_signature, booted into 7.0.0-38-generic)
+ - lspci-vnvn.log (sudo lspci -vnvn, Device Serial Number lines redacted)
+ - lsb_release.log (lsb_release -rd)
+ - apt-cache-policy.log (apt-cache policy for the kernel, firmware, Mesa,
libdrm and KWin packages)
The logs are filtered to kernel, KWin, plasmashell, systemd-logind and
Plasma user service messages. Lines about networking, audit/AppArmor,
Secure Boot certificates, Bluetooth, storage encryption and unrelated
userspace crashes were removed. Hostname, username, MAC/IP addresses and
UUIDs were redacted. Unfiltered logs, or specific sections of them, are
available on request.
Happy to test patches, kernels or further options.
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https://bugs.launchpad.net/bugs/2171560
Title:
[TU117] nouveau on 7.0.0-38: external DP monitors via Thunderbolt dock
show no signal (GSP); with NvGspRm=0, KWin GPU job timeouts. Works on
6.8.0-147
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2171560/+subscriptions
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