Bug 2531653
| Summary: | COSMIC fails to start from Live ISO: cosmic-comp cannot open /dev/dri/card1 (Device or resource busy) | ||||||||||||||
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| Product: | [Fedora] Fedora | Reporter: | Geraldo Simião <geraldo.simiao.kutz> | ||||||||||||
| Component: | cosmic-comp | Assignee: | Ryan Brue <ryanbrue.dev> | ||||||||||||
| Status: | CLOSED ERRATA | QA Contact: | |||||||||||||
| Severity: | high | Docs Contact: | |||||||||||||
| Priority: | unspecified | ||||||||||||||
| Version: | 45 | CC: | cosmic-sig, ephmo, f_rkan_aktas, jfalempe, jgroman, kparal.oss, rust-sig, ryanbrue.dev, yardquit | ||||||||||||
| Target Milestone: | --- | Keywords: | CommonBugs, Desktop, Regression | ||||||||||||
| Target Release: | --- | Flags: | kparal.oss:
needinfo?
(geraldo.simiao.kutz) |
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| Hardware: | Unspecified | ||||||||||||||
| OS: | Linux | ||||||||||||||
| Whiteboard: | https://discussion.fedoraproject.org/t/common-issue/201696 | ||||||||||||||
| Fixed In Version: | Doc Type: | --- | |||||||||||||
| Doc Text: | Story Points: | --- | |||||||||||||
| Clone Of: | Environment: | ||||||||||||||
| Last Closed: | 2026-09-27 00:29:12 UTC | Type: | --- | ||||||||||||
| Regression: | --- | Mount Type: | --- | ||||||||||||
| Documentation: | --- | CRM: | |||||||||||||
| Verified Versions: | Category: | --- | |||||||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||||||
| Embargoed: | |||||||||||||||
| Attachments: |
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Created attachment 2157472 [details]
1 Srcreenshot from journalctl -r
Created attachment 2157473 [details]
2 Screenshot from journalctl -r
Created attachment 2157474 [details]
3 Screenshot from journalctl -r
I can confirm that F45 Beta 1.3 Cosmic indeed doesn’t work. I installed Cosmic DE using the netinst ISO just to confirm what I suspected. The problem seems to be that start-cosmic cannot be launched from the console when using kmscon. Removing kmscon and enabling getty@.service makes it possible to launch start-cosmic successfully. Workaround for COSMIC Live image courtesy of GPT-5.6 Terra: - At the login prompt login as liveuser with no password - Run: sudo systemd-run --unit=cosmic-kmscon-test --collect /bin/sh -c 'systemctl stop kmsconvt; systemctl restart cosmic-greeter.service' Apparently one possible fix would be cosmic-greeter.service declaring Conflicts also with kmscon: # cosmic-greeter.service [Unit] Conflicts=kmsconvt getty After=kmsconvt getty Common issue documentation: https://discussion.fedoraproject.org/t/common-issue/201696 Created attachment 2157946 [details]
error log after trying to use the workarround
I used the same cosmic spin iso (beta 1.3) and tried to apply the workarround but it dindn't work.
Created attachment 2157947 [details]
error log after trying to use the workarround 2
I see that I have a typo at the first try. I corrected it but still don't managed to work.
Geraldo, you need to use simple quotes, not backticks. Please try with those. I just submitted a PR upstream: https://github.com/pop-os/cosmic-greeter/pull/546 We should backport it to the rpm package. And here is the PR for the Fedora package: https://src.fedoraproject.org/rpms/cosmic-greeter/pull-request/2 FEDORA-2026-3664f42714 (cosmic-greeter-1.8.0-3.fc43) has been submitted as an update to Fedora 43. https://bodhi.fedoraproject.org/updates/FEDORA-2026-3664f42714 FEDORA-2026-ca2380fb28 (cosmic-greeter-1.8.0-3.fc44) has been submitted as an update to Fedora 44. https://bodhi.fedoraproject.org/updates/FEDORA-2026-ca2380fb28 FEDORA-2026-0a3adea698 has been pushed to the Fedora 45 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-0a3adea698` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-0a3adea698 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates. FEDORA-2026-ca2380fb28 has been pushed to the Fedora 44 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-ca2380fb28` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-ca2380fb28 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates. FEDORA-2026-3664f42714 has been pushed to the Fedora 43 testing repository. Soon you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-3664f42714` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-3664f42714 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates. FEDORA-2026-0a3adea698 (cosmic-greeter-1.8.0-3.fc45) has been pushed to the Fedora 45 stable repository. If problem still persists, please make note of it in this bug report. FEDORA-2026-ca2380fb28 (cosmic-greeter-1.8.0-3.fc44) has been pushed to the Fedora 44 stable repository. If problem still persists, please make note of it in this bug report. FEDORA-2026-3664f42714 (cosmic-greeter-1.8.0-3.fc43) has been pushed to the Fedora 43 stable repository. If problem still persists, please make note of it in this bug report. Geraldo, can you please verify whether this was indeed fixed? Thanks a lot! Same issue on an installed system (not the Live ISO): Fedora 44 KDE with the
COSMIC package group added, logging into COSMIC from SDDM.
Hardware: Lenovo ThinkPad 21MDS00E00, AMD iGPU 1002:1900, kernel 7.2.9-200.fc44.
cosmic-comp fails at session start with:
cosmic-comp: Failed to add device /dev/dri/card1: Failed to obtain file descriptor for drm device: /dev/dri/card1
Caused by: Failed to open device: Device or resource busy (os error 16)
cosmic-comp: Error occured in main(): Backend initialized without output
cosmic-session: cosmic-comp exited with error code 1
cosmic-session: cosmic-comp exited with error code 137
In the same second, SDDM's Wayland greeter is still shutting down:
sddm-helper-start-wayland: Stopping... "kwin_wayland"
sddm-helper: Starting Wayland user session: "/etc/sddm/wayland-session" "/usr/bin/start-cosmic"
So this looks like a race in the DRM device handoff: kwin_wayland (greeter)
hasn't released card1 yet when cosmic-comp tries to open it, and cosmic-comp
gives up instead of retrying. Plasma sessions from the same SDDM are unaffected.
- Starting COSMIC from a TTY with SDDM stopped works.
- Workaround: a session entry whose Exec is a wrapper script that runs
"sleep 2" before "exec start-cosmic" avoids the black screen.
Note for others with AMD laptops: a separate display freeze after COSMIC
reaches the desktop turned out to be an amdgpu PSR regression in 7.2
(workaround amdgpu.dcdebugmask=0x10), reported upstream here:
https://gitlab.freedesktop.org/drm/amd/-/work_items/5957
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The Fedora 45 COSMIC Beta 13 Live ISO fails to start a graphical COSMIC session. The system boots to a TTY and cosmic-session is started, but cosmic-comp fails when trying to acquire the DRM device /dev/dri/card1. The journal reports: "Failed to add device /dev/dri/card1: Failed to obtain file descriptor for drm device: /dev/dri/card1" followed by: "Failed to open device: Device or resource busy (os error 16)" and: "Backend initialized without output" cosmic-comp then exits and cosmic-session attempts to restart it. The issue was reproduced in QEMU/KVM with and without graphics acceleration. Another tester also seems to reproduce the issue on physical hardware. For comparison, Fedora 44 Respin (2026-09-01) works correctly using the same VM configuration. Reproducible: Always Steps to Reproduce: 1. Boot the Fedora 45 COSMIC Beta 13 Live ISO. 2. Wait for the system to finish booting. Actual Results: The Live session does not reach the COSMIC desktop and instead remains at a TTY login prompt. Expected Results: The Fedora 45 COSMIC Live session should complete the boot process and automatically start a fully functional COSMIC graphical desktop session, without requiring the user to log in manually or start the graphical session from a TTY. Additional Information: Test environment: Static hostname: localhost-live Icon name: computer-vm Chassis: vm Virtualization: kvm Operating System: Fedora Linux 45 (COSMIC Prerelease) CPE OS Name: cpe:/o:fedoraproject:fedora:45 Kernel: Linux 7.2.0-61.fc45.x86_64 Architecture: x86-64 Hardware Vendor: QEMU Hardware Model: Standard PC _Q35 + ICH9, 2009_ Hardware Version: pc-q35-11.1 Firmware Version: edk2-20260812-5.fc45 Firmware Date: Wed 2026-08-12 The VM has graphics acceleration enabled. Relevant journal entries (journalctl -r): Sep 10 19:36:45 localhost-live cosmic-session[1977]: Starting process 'COSMIC_SESSION_SOCK=12 cosmic-comp' Sep 10 19:36:47 localhost-live cosmic-comp[2199]: error loading system dark theme Sep 10 19:36:47 localhost-live cosmic-comp[2199]: shortcuts custom config error: GetKey("custom"), Os { code: 2, kind: NotFound, message: "No such file or directory" } Sep 10 19:36:49 localhost-live cosmic-comp[2199]: Failed to add device /dev/dri/card1: Failed to obtain file descriptor for drm device: /dev/dri/card1 Caused by: Failed to open device: Device or resource busy (os error 16) Sep 10 19:36:49 localhost-live cosmic-comp[2199]: Error occured in main(): Backend initialized without output Sep 10 19:36:49 localhost-live cosmic-session[1977]: cosmic-comp exited with error code 1 Sep 10 19:36:59 localhost-live cosmic-session[1977]: restarted process 'COSMIC_SESSION_SOCK=12 cosmic-comp', now at 1 restarts Sep 10 19:36:59 localhost-live cosmic-session[1977]: sleeping for 2ms before restarting process cosmic-comp (restart 0) Sep 10 19:36:59 localhost-live cosmic-session[1977]: draining stdin receiver before restarting process Sep 10 19:37:01 localhost-live cosmic-session[1977]: cosmic-comp exited with error code 137