Public bug reported: Summary: Upgrading linux-firmware to 20240318.git3b128b60-0ubuntu2.29 breaks display output on RX 6800-class cards (DCN 3.0 / Navi 21). First symptom appears at the GDM login screen (the first full-resolution DMUB-driven modeset): right half of the display shows vertical stripes/artefacts, followed by black screens and a GPU reset loop (sdma1 ring timeout → MODE1 reset) that repeatedly kills the X session. Splash renders fine; framebuffer captures are clean — corruption is in the display output path (DMUB), not rendering. OSD/monitor menu is crisp, ruling out panel failure.
Log evidence (every boot with .29): [drm] Loading DMUB firmware via PSP: version=0x01000000 [drm] Wait for DMUB auto-load failed: 3 [drm] DMUB hardware initialized: version=0x01000000 Healthy boots (≤ .27) show version=0x02020020 with no auto-load failure. All nine dcn_*_dmcub.bin files differ between .26 and .29 (md5-verified). System: Ubuntu 24.04.4, kernel 6.8.0-137-lowlatency (also reproduced on 6.8.0-136-lowlatency — kernel-agnostic), Sapphire RX 6800, DP at 2560x1440@60. Workaround: apt-mark hold linux-firmware + downgrade to 20240318.git3b128b60-0ubuntu2.26 (noble-security). Display fully restored across cold boots. Related reports: https://forums.linuxmint.com/viewtopic.php?t=472692 (identical GPU/kernel/package, fixed by rollback) https://forums.linuxmint.com/viewtopic.php?t=472727 (RX 6800/6900, same symptoms) (2/3) https://github.com/NixOS/nixpkgs/issues/419838 (DMCUB load failure after firmware update) Reddit r/linux_gaming: "amdgpu users: avoid updating linux-firmware right now" ** Affects: linux-firmware (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2163388 Title: linux-firmware 0ubuntu2.29 breaks amdgpu DMUB on Radeon RX 6800 (Navi 21): stripes/artefacts from login screen, GPU reset loop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/2163388/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
