Public bug reported: # SUMMARY
On noble, xorg-server 2:21.1.12-1ubuntu1.7 and later fail to start on this hybrid AMD + NVIDIA laptop when an external monitor is connected to the NVIDIA GPU. The server exits with: (EE) modeset(G0): Failed to create pixmap (EE) Fatal server error: (EE) failed to create screen resources 2:21.1.12-1ubuntu1.5 works on the same kernel, same driver, same monitor. # ENVIRONMENT Linux Mint 22.3 (noble base), X11 / Cinnamon, LightDM Kernel 7.0.0-42-generic ASUS ROG Zephyrus G16 GA605WI, BIOS GA605WI.316 (2025-07-24) 64:00.0 VGA [0300]: NVIDIA RTX 4070 Max-Q [10de:2860], Acer R271 on HDMI 65:00.0 Display [0380]: AMD Radeon 890M [1002:150e], internal panel eDP-1 nvidia-driver-615-open 615.71.09-0ubuntu0.24.04.2 The xserver packages are unmodified Ubuntu packages from noble-updates and noble-security. No PPA or third-party build is involved. # PACKAGE VERSIONS $ apt-cache policy xserver-xorg-core xserver-xorg-core: Installed: 2:21.1.12-1ubuntu1.5 Candidate: 2:21.1.12-1ubuntu1.9 Version table: 2:21.1.12-1ubuntu1.9 500 500 http://.../ubuntu noble-updates/main amd64 Packages *** 2:21.1.12-1ubuntu1.5 500 500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages 100 /var/lib/dpkg/status 2:21.1.12-1ubuntu1 500 500 http://.../ubuntu noble/main amd64 Packages xserver-common, xserver-xorg-legacy and xserver-xephyr are at the same version as xserver-xorg-core in each run. # EXPECTED X starts and drives both the internal panel and the HDMI monitor, as it does with 2:21.1.12-1ubuntu1.5. # ACTUAL X exits during server initialisation. LightDM restarts it in a loop and the machine stays on a text console. # REPRODUCTION 1. Boot with an external monitor connected to the NVIDIA HDMI output. 2. Install xserver-xorg-core 2:21.1.12-1ubuntu1.7 or later from noble-updates. 3. Start X (systemctl restart lightdm). 4. X exits with the error above. # CAUSE 1ubuntu1.7 backports upstream MR !2242 ("xfree86: prefer boot_display over boot_vga for primary device"). On this machine /sys/class/drm/card1/boot_display is 1, the AMD iGPU, so the patch makes the AMD the primary device and demotes the NVIDIA to a secondary GPU screen driven by modesetting. The modesetting driver then tries to allocate a pixmap on the NVIDIA through GBM/EGL and fails. The failing call is drmmode_set_pixmap_bo() -> egl_create_textured_pixmap_from_gbm_bo() at hw/xfree86/drivers/modesetting/drmmode_display.c:3619. 1ubuntu1.8 carries the same patch. 1ubuntu1.9 adds unrelated DisplayLink/evdi fixes (LP #2160643) but is cumulative, so it still contains the regression. CONTROLLED COMPARISON Same kernel 7.0.0-42, same NVIDIA 615.71.09, Acer R271 on HDMI in both runs. Only the xserver version differs. 1ubuntu1.5 1ubuntu1.9 Primary device (PCI:*) 10de:2860 NVIDIA 1002:150e AMD NVIDIA(0) lines in log 33 0 modeset(G0) glamor AMD 890M NVIDIA RTX 4070 pixmap errors 0 1 In 1.5 the NVIDIA is the primary screen and drives the monitor: (II) NVIDIA(0): Setting mode "DFP-2:nvidia-auto-select" In 1.9 the NVIDIA is demoted to modeset(G0) and the server dies before it can set a mode. # WHY SRU VERIFICATION DID NOT CATCH THIS The verification on bug #2136140 comment #31 used an AMD + NVIDIA system with no display attached to the NVIDIA. In that configuration the NVIDIA stays in D3cold and no modesetting GPU screen is created, so this path is not exercised. Reproducing this report needs a monitor on the dGPU. # RELATED Bug #2161262 reports the same (EE) modeset(G0): Failed to create pixmap from the modesetting driver claiming the NVIDIA as a GPU screen, with a different trigger. # WORKAROUND Hold the four packages at 2:21.1.12-1ubuntu1.5: sudo apt-mark hold xserver-xorg-core xserver-common xserver-xorg- legacy xserver-xephyr # NOTES Filed manually rather than with ubuntu-bug xorg-server because the machine is currently running the working 1.5 packages, so ubuntu-bug would collect the working state rather than the failing one. The equivalent information is included above and in the attachments. The attached logs are verbatim except for three substitutions: HOSTNAME, REDACTED-FS-UUID, and EDID serial (as REDACTED). (Report drafted with AI assistance; all tests were manually performed and verified on this machine.) ** Affects: xorg-server (Ubuntu) Importance: Undecided Status: New ** Tags: regression-update ** Attachment added: "Xorg.0.log-1ubuntu1.9-fail.txt" https://bugs.launchpad.net/bugs/2173622/+attachment/6015764/+files/Xorg.0.log-1ubuntu1.9-fail.txt ** Description changed: - SUMMARY + # SUMMARY On noble, xorg-server 2:21.1.12-1ubuntu1.7 and later fail to start on this hybrid AMD + NVIDIA laptop when an external monitor is connected to the NVIDIA GPU. The server exits with: - (EE) modeset(G0): Failed to create pixmap - (EE) Fatal server error: - (EE) failed to create screen resources + (EE) modeset(G0): Failed to create pixmap + (EE) Fatal server error: + (EE) failed to create screen resources 2:21.1.12-1ubuntu1.5 works on the same kernel, same driver, same monitor. - ENVIRONMENT + # ENVIRONMENT - Linux Mint 22.3 (noble base), X11 / Cinnamon, LightDM - Kernel 7.0.0-42-generic - ASUS ROG Zephyrus G16 GA605WI, BIOS GA605WI.316 (2025-07-24) - 64:00.0 VGA [0300]: NVIDIA RTX 4070 Max-Q [10de:2860], Acer R271 on HDMI - 65:00.0 Display [0380]: AMD Radeon 890M [1002:150e], internal panel eDP-1 - nvidia-driver-615-open 615.71.09-0ubuntu0.24.04.2 + Linux Mint 22.3 (noble base), X11 / Cinnamon, LightDM + Kernel 7.0.0-42-generic + ASUS ROG Zephyrus G16 GA605WI, BIOS GA605WI.316 (2025-07-24) + 64:00.0 VGA [0300]: NVIDIA RTX 4070 Max-Q [10de:2860], Acer R271 on HDMI + 65:00.0 Display [0380]: AMD Radeon 890M [1002:150e], internal panel eDP-1 + nvidia-driver-615-open 615.71.09-0ubuntu0.24.04.2 The xserver packages are unmodified Ubuntu packages from noble-updates and noble-security. No PPA or third-party build is involved. - PACKAGE VERSIONS + # PACKAGE VERSIONS - $ apt-cache policy xserver-xorg-core - xserver-xorg-core: - Installed: 2:21.1.12-1ubuntu1.5 - Candidate: 2:21.1.12-1ubuntu1.9 - Version table: - 2:21.1.12-1ubuntu1.9 500 - 500 http://.../ubuntu noble-updates/main amd64 Packages - *** 2:21.1.12-1ubuntu1.5 500 - 500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages - 100 /var/lib/dpkg/status - 2:21.1.12-1ubuntu1 500 - 500 http://.../ubuntu noble/main amd64 Packages + $ apt-cache policy xserver-xorg-core + xserver-xorg-core: + Installed: 2:21.1.12-1ubuntu1.5 + Candidate: 2:21.1.12-1ubuntu1.9 + Version table: + 2:21.1.12-1ubuntu1.9 500 + 500 http://.../ubuntu noble-updates/main amd64 Packages + *** 2:21.1.12-1ubuntu1.5 500 + 500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages + 100 /var/lib/dpkg/status + 2:21.1.12-1ubuntu1 500 + 500 http://.../ubuntu noble/main amd64 Packages xserver-common, xserver-xorg-legacy and xserver-xephyr are at the same version as xserver-xorg-core in each run. - EXPECTED + # EXPECTED X starts and drives both the internal panel and the HDMI monitor, as it does with 2:21.1.12-1ubuntu1.5. - ACTUAL + # ACTUAL X exits during server initialisation. LightDM restarts it in a loop and the machine stays on a text console. - REPRODUCTION + # REPRODUCTION 1. Boot with an external monitor connected to the NVIDIA HDMI output. 2. Install xserver-xorg-core 2:21.1.12-1ubuntu1.7 or later from noble-updates. 3. Start X (systemctl restart lightdm). 4. X exits with the error above. - CAUSE + # CAUSE 1ubuntu1.7 backports upstream MR !2242 ("xfree86: prefer boot_display over boot_vga for primary device"). On this machine /sys/class/drm/card1/boot_display is 1, the AMD iGPU, so the patch makes the AMD the primary device and demotes the NVIDIA to a secondary GPU screen driven by modesetting. The modesetting driver then tries to allocate a pixmap on the NVIDIA through GBM/EGL and fails. The failing call is drmmode_set_pixmap_bo() -> egl_create_textured_pixmap_from_gbm_bo() at hw/xfree86/drivers/modesetting/drmmode_display.c:3619. 1ubuntu1.8 carries the same patch. 1ubuntu1.9 adds unrelated DisplayLink/evdi fixes (LP #2160643) but is cumulative, so it still contains the regression. - CONTROLLED COMPARISON Same kernel 7.0.0-42, same NVIDIA 615.71.09, Acer R271 on HDMI in both runs. Only the xserver version differs. - 1ubuntu1.5 1ubuntu1.9 - Primary device (PCI:*) 10de:2860 NVIDIA 1002:150e AMD - NVIDIA(0) lines in log 33 0 - modeset(G0) glamor AMD 890M NVIDIA RTX 4070 - pixmap errors 0 1 + 1ubuntu1.5 1ubuntu1.9 + Primary device (PCI:*) 10de:2860 NVIDIA 1002:150e AMD + NVIDIA(0) lines in log 33 0 + modeset(G0) glamor AMD 890M NVIDIA RTX 4070 + pixmap errors 0 1 In 1.5 the NVIDIA is the primary screen and drives the monitor: - (II) NVIDIA(0): Setting mode "DFP-2:nvidia-auto-select" + (II) NVIDIA(0): Setting mode "DFP-2:nvidia-auto-select" In 1.9 the NVIDIA is demoted to modeset(G0) and the server dies before it can set a mode. - WHY SRU VERIFICATION DID NOT CATCH THIS + # WHY SRU VERIFICATION DID NOT CATCH THIS The verification on bug #2136140 comment #31 used an AMD + NVIDIA system with no display attached to the NVIDIA. In that configuration the NVIDIA stays in D3cold and no modesetting GPU screen is created, so this path is not exercised. Reproducing this report needs a monitor on the dGPU. - RELATED + # RELATED Bug #2161262 reports the same (EE) modeset(G0): Failed to create pixmap from the modesetting driver claiming the NVIDIA as a GPU screen, with a different trigger. - WORKAROUND + # WORKAROUND Hold the four packages at 2:21.1.12-1ubuntu1.5: - sudo apt-mark hold xserver-xorg-core xserver-common xserver-xorg- + sudo apt-mark hold xserver-xorg-core xserver-common xserver-xorg- legacy xserver-xephyr - NOTES + # NOTES Filed manually rather than with ubuntu-bug xorg-server because the machine is currently running the working 1.5 packages, so ubuntu-bug would collect the working state rather than the failing one. The equivalent information is included above and in the attachments. The attached logs are verbatim except for three substitutions: HOSTNAME, REDACTED-FS-UUID, and EDID serial (as REDACTED). - (Report drafted with AI assistance; all tests were manually performed and verified on this machine.) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2173622 Title: xorg-server 1ubuntu1.7+: X fails to start on AMD+NVIDIA hybrid when a monitor is attached to the dGPU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/2173622/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
