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Read more about Launchpad's inter-bugtracker facilities at https://documentation.ubuntu.com/launchpad/user/reference/bugs/multi-project-bugs/about-multi-project-bugs/#bugs-in-external-trackers. ------------------------------------------------------------------------ On 2026-09-14T07:53:29+00:00 undercover_black_hat wrote: ## Description The `amd-gpu-firmware` update from `20260810-1.fc44` to `20260910-1.fc44` ships a **lower** DMCUB microcode version for YELLOW_CARP (DCN 3.1.2) than the package it replaces: | Package | `yellow_carp_dmcub.bin` ucode_version | |------------------------------|---------------------------------------| | amd-gpu-firmware-20260309-1 | `0x04000047` | | amd-gpu-firmware-20260810-1 | `0x0400004C` (works) | | amd-gpu-firmware-20260910-1 | `0x0400004A` (**regression**) | Verified by decompressing the shipped blob and reading `ucode_version` at offset 0x10 of the common firmware header: # amd-gpu-firmware-20260910-1.fc44 (installed) 00000010 4a 00 00 04 10 97 03 00 00 01 00 00 1a fc f8 2a |J..............*| sha256: 5cdaaa2c159b0742d38cb655311550a5c4dfefe9bdf12c0fc02d8f14fce781a2 # amd-gpu-firmware-20260810-1.fc44 (previous) 00000010 4c 00 00 04 10 99 03 00 00 01 00 00 79 00 f3 aa |L...........y...| sha256: 3f871acbdb93e5c9aac03805abd597c59bd220388f3e37dc9ccc2cf21c884b6f The PSP refuses to authenticate the 0x0400004A image, DMUB never starts, and the eDP link to the internal panel fails to train. The machine boots completely (networking, gdm, and the GNOME Shell Wayland greeter all start normally) but the panel stays dark, so it presents to the user as a boot failure. ## Actual results amdgpu 0000:06:00.0: [drm] Loading DMUB firmware via PSP: version=0x0400004A amdgpu 0000:06:00.0: failed to load ucode DMCUB(0x3F) amdgpu 0000:06:00.0: psp gfx command LOAD_IP_FW(0x6) failed and response status is (0xFFFF0008) amdgpu 0000:06:00.0: [drm] Wait for DMUB auto-load failed: 3 amdgpu 0000:06:00.0: [drm] *ERROR* Error getting DMUB FW meta info: 4 amdgpu 0000:06:00.0: [drm] *ERROR* dc_dmub_srv_log_diagnostic_data: DMCUB error - collecting diagnostic data ... (repeats 126-231 times per boot) ... amdgpu 0000:06:00.0: [drm] enabling link 0 failed: 15 ## Expected results DMUB loads and the internal panel lights up, as with 20260810-1: amdgpu 0000:06:00.0: [drm] Loading DMUB firmware via PSP: version=0x0400004C amdgpu 0000:06:00.0: [drm] DMUB hardware initialized: version=0x0400004C (zero DMCUB errors, no link-enable failure) ## Steps to Reproduce 1. Rembrandt / Radeon 680M system (DCN 3.1.2, YELLOW_CARP) running amd-gpu-firmware-20260810-1.fc44. 2. `sudo dnf update` -> amd-gpu-firmware-20260910-1.fc44 installed, initramfs regenerated. 3. Reboot. Panel stays black; the system is otherwise up and reachable. ## Hardware - ASUSTeK ROG Zephyrus G15 GA503RS, BIOS GA503RS.317 (02/27/2024) - AMD Ryzen 9 6900HS with Radeon Graphics - iGPU: Rembrandt [Radeon 680M] [1002:1681] rev c7, subsystem [1043:13dd] (amdgpu) - dGPU: NVIDIA GA104M [RTX 3080 Mobile] [10de:249c] (nvidia, blacklisted nouveau/nova_core) - UEFI boot, Secure Boot disabled ## Additional info **This is not kernel-specific.** It reproduces purely from the firmware change; the same regression is reported on Arch and CachyOS across unrelated kernels: - https://bbs.archlinux.org/viewtopic.php?pid=2309459#p2309459 (independently reports the identical version pair: 20260910-1 = 0x0400004A broken, 20260810-2 = 0x0400004C working) - https://discuss.cachyos.org/t/regression-linux-firmware-amdgpu-20260910-1-dmcub-fails-to-load-on-amd-radeon-680m-rembrandt-causing-slow-boot-and-visual-glitches/35623 Other hardware reported affected in those threads: Radeon 9070 XT, 9060 XT, 7700S, and Raphael. Severity varies -- some users see only slow boot and visual glitches, others (as here) a completely dark panel. **The regression can be masked on the previously-installed kernel.** An older kernel whose initramfs predates the firmware update still carries the 0x0400004C blob and boots fine, which makes this look like a kernel regression rather than a firmware one. Regenerating that initramfs (`dracut -f`) breaks the older kernel too. **Workaround** (avoids downgrading the whole version-locked firmware package set, which would also revert amd-ucode-firmware/CPU microcode): sudo install -D -m 0644 yellow_carp_dmcub.bin.xz \ /lib/firmware/updates/amdgpu/yellow_carp_dmcub.bin.xz # from 20260810-1 sudo restorecon -Rv /lib/firmware/updates/amdgpu sudo dracut -f --regenerate-all **Suggested fix:** revert `yellow_carp_dmcub.bin` to the 0x0400004C build from 20260810, or rebase to a DMCUB release >= 0x0400004C. Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/0 ------------------------------------------------------------------------ On 2026-09-14T09:57:14+00:00 pbrobinson wrote: Mario: is this a known issue? Seemingly caused by upstream commit ed94b3559 Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/1 ------------------------------------------------------------------------ On 2026-09-14T12:15:39+00:00 kkushagra86 wrote: Confirming identical regression on a second OEM and APU model (MSI Thin A15 with Ryzen 5 7535HS / Radeon 660M): Hardware: - Model: MSI Thin A15 B7UCX - BIOS: E16RKAMS.10E - CPU: AMD Ryzen 5 7535HS with Radeon Graphics - iGPU: Rembrandt [Radeon 660M] [1002:1681] rev 0b, subsystem [1462:1437] - dGPU: NVIDIA GeForce RTX 2050 Mobile [10de:25ad] rev a1, subsystem [1462:1437] - Kernel: 7.2.5-200.fc44.x86_64 Symptoms: Immediately upon updating to amd-gpu-firmware-20260910-1.fc44 and rebooting, the internal eDP display remains completely black with no Plymouth splash and no GDM output. dmesg shows the exact same PSP rejection and DMCUB load failure: amdgpu 0000:05:00.0: [drm] Loading DMUB firmware via PSP: version=0x0400004A amdgpu 0000:05:00.0: [drm] *ERROR* Error getting DMUB FW meta info: 4 amdgpu 0000:05:00.0: failed to load ucode DMCUB(0x3F) amdgpu 0000:05:00.0: psp gfx command LOAD_IP_FW(0x6) failed and response status is (0xFFFF0008) amdgpu 0000:05:00.0: [drm] *ERROR* Error queueing DMUB command: status=2 Workaround verified: Copying yellow_carp_dmcub.bin.xz (version 0x0400004C, SHA256: 3f871acbdb93e5c9aac03805abd597c59bd220388f3e37dc9ccc2cf21c884b6f) from amd-gpu-firmware-20260810-1.fc44 back into /usr/lib/firmware/amdgpu/ and rebuilding initramfs with dracut completely restores display functionality on kernel 7.2.5-200.fc44.x86_64. Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/2 ------------------------------------------------------------------------ On 2026-09-14T13:56:08+00:00 mario.limonciello wrote: Sorry folks of the issue. But thanks for gathering all the details and bisecting down to the specific commit that caused it. I've sent up the revert: https://gitlab.com/kernel-firmware/linux-firmware/-/merge_requests/1241 We'll investigate internally what went wrong with this one. Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/3 ------------------------------------------------------------------------ On 2026-09-14T14:04:49+00:00 pbrobinson wrote: We'll land this in Fedora with the next tagged upstream release, in the meantime it's likely easiest for the users hitting this to downgrade. Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/4 ------------------------------------------------------------------------ On 2026-09-14T18:06:37+00:00 pbrobinson wrote: *** Bug 2533250 has been marked as a duplicate of this bug. *** Reply at: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd- graphics/+bug/2167279/comments/5 ** Changed in: linux-firmware-amd-graphics (Fedora) Status: Unknown => In Progress ** Changed in: linux-firmware-amd-graphics (Fedora) Importance: Unknown => High -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2167279 Title: Regression in 20260911.giteeccccbe-0ubuntu1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware-amd-graphics/+bug/2167279/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
