Public bug reported:

Ubuntu 24.04.4 LTS
linux-firmware 20240318.git3b128b60-0ubuntu2.29
Kernel 7.0.0-29-generic (also reproduced on 7.0.0-28-generic)
GPU: Navi 21 [1002:73bf] Radeon RX 6900 XT (XFX Speedster MERC 319)
Displays: DisplayPort [email protected], HDMI 1920x1080@60

After upgrading to linux-firmware 0ubuntu2.29, the right half of the
primary DisplayPort monitor is permanently black. The hardware cursor is
still drawn correctly inside the black region, and a screenshot of the X
root window shows the full desktop rendered correctly, so the
framebuffer content is intact and the failure is in the DCN display
pipeline.

Any modeset makes it much worse: changing the refresh rate via xrandr,
or rearranging monitors in GNOME Settings, blanks both outputs
completely and requires a hard reset. The kernel log reports no DRM
errors at all, no link training failures, no underflow, no AER errors.
GPU temperature is normal and the driver reports a valid mode.

Downgrading the kernel does not help. The same hardware is unaffected
under Windows.

Root cause:

Comparing the 12 sienna_cichlid firmware files between 0ubuntu2.26 and
0ubuntu2.29, exactly one changed, sienna_cichlid_dmcub.bin.zst.
Everything else (ce, me, mec, mec2, pfp, rlc, sdma, smc, sos, ta, vcn)
is bit-for-bit identical.

In 0ubuntu2.26 and earlier:
  sienna_cichlid_dmcub.bin.zst -> symlink to beige_goby_dmcub.bin.zst
  sha256 e095010915468c30598c1118b0d955762e49f08f9e835fe5d1f9ecb0788fb016
  74553 bytes compressed, 114036 bytes uncompressed

In 0ubuntu2.29:
  sienna_cichlid_dmcub.bin.zst is a separate file
  sha256 25bea6217254e43387dfdf444d8f90c26929ade2dd793c5db7fb9b37ab83e3fe
  37726 bytes compressed, 69876 bytes uncompressed

The DMUB version reported by the driver goes backwards with the new
file:

  broken (0ubuntu2.29):  amdgpu: [drm] DMUB hardware initialized: 
version=0x01000000
  working (via symlink): amdgpu: [drm] DMUB hardware initialized: 
version=0x02020020

A DMCUB image reporting version 1.0.0.0, which is lower than the
2.2.0.32 previously shipped for this ASIC, and roughly 60% of its size,
suggests the wrong binary was packaged for sienna_cichlid.

Workaround, restores the previous behaviour and survives package
upgrades:

  sudo dpkg-divert --divert 
/lib/firmware/amdgpu/sienna_cichlid_dmcub.bin.zst.229 --rename 
/lib/firmware/amdgpu/sienna_cichlid_dmcub.bin.zst
  sudo ln -s beige_goby_dmcub.bin.zst 
/lib/firmware/amdgpu/sienna_cichlid_dmcub.bin.zst
  sudo update-initramfs -u

After a reboot the display works normally on the current 7.0.0-29
kernel.

Other users report the same regression on Navi 21 hardware after the 2.26 to 
2.29 upgrade:
https://forums.linuxmint.com/viewtopic.php?t=472692

Please revert sienna_cichlid_dmcub.bin to the beige_goby symlink, or
ship a correct DMCUB image for this ASIC.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-firmware 20240318.git3b128b60-0ubuntu2.29
ProcVersionSignature: Ubuntu 7.0.0-29.29~24.04.2-generic 7.0.12
Uname: Linux 7.0.0-29-generic x86_64
ApportVersion: 2.28.3-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
 USER        PID ACCESS COMMAND
 /dev/snd/controlC2:  pavel      2607 F.... wireplumber
 /dev/snd/controlC0:  pavel      2607 F.... wireplumber
 /dev/snd/controlC1:  pavel      2607 F.... wireplumber
 /dev/snd/seq:        pavel      2603 F.... pipewire
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Aug 18 16:34:04 2026
Dependencies: firmware-sof-signed 2023.12.1-1ubuntu1.11
InstallationDate: Installed on 2025-05-24 (451 days ago)
InstallationMedia: Ubuntu 24.04.2 LTS "Noble Numbat" - Release amd64 (20250215)
MachineType: Gigabyte Technology Co., Ltd. B760M DS3H
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-29-generic 
root=UUID=a8dd2857-db7d-4a38-acd4-4090fa2ab137 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-7.0.0-29-generic N/A
 linux-backports-modules-7.0.0-29-generic  N/A
 linux-firmware                            20240318.git3b128b60-0ubuntu2.29
RfKill:
 
SourcePackage: linux-firmware
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/13/2026
dmi.bios.release: 5.27
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: F24
dmi.board.asset.tag: Default string
dmi.board.name: B760M DS3H
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: 
dmi:bvnAmericanMegatrendsInternational,LLC.:bvrF24:bd06/13/2026:br5.27:svnGigabyteTechnologyCo.,Ltd.:pnB760MDS3H:pvrDefaultstring:rvnGigabyteTechnologyCo.,Ltd.:rnB760MDS3H:rvrx.x:cvnDefaultstring:ct3:cvrDefaultstring:skuDefaultstring:pfaB760MB:
dmi.product.family: B760 MB
dmi.product.name: B760M DS3H
dmi.product.sku: Default string
dmi.product.version: Default string
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

** Affects: linux-firmware (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug noble

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2163762

Title:
  linux-firmware 2.29: broken sienna_cichlid_dmcub.bin breaks display
  output on Navi 21 (RX 6900 XT)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/2163762/+subscriptions


-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to