Hello, I'm new to linux and have had ChatGPT help me compile this :) I'm reporting another affected laptop with the same AMD Barcelo GPU and very similar symptoms. My system is an Acer Aspire AL15-45P with a Ryzen 7 5825U.
### Hardware - Laptop: Acer Aspire AL15-45P - CPU: AMD Ryzen 7 5825U - GPU: AMD Barcelo integrated graphics - PCI ID: 1002:15e7, revision c1 - Subsystem ID: 1025:2066 - Display architecture: DCN 2.1 - DMUB firmware: 0x0101002B - BIOS: V1.16 (DMI date 08/04/2026) ### Software - Ubuntu 26.04.1 LTS - Kernel 7.0.0-42-generic (7.0.0-42.42) - Kernel 7.0.0-30-generic (7.0.0-30.30) - Kernel 6.17.0-35-generic (6.17.0-35.35~24.04.1) - Linux firmware: 20260319.git217ca6e4.1ubuntu - KDE Plasma 6.6.6 - Wayland session ### Kernel comparison Kernel 6.17.0-35 initializes the internal laptop display and external HDMI display correctly without additional boot parameters. Kernels 7.0.0-30 and 7.0.0-42 have both exhibited internal display initialization failures. The problem is intermittent on subsequent 7.0 boots. ### Failure messages On affected 7.0 boots, the kernel reports: - Failed to enable ASSR. - DPCD write failure: DP_DOWNSPREAD_CTRL. - DPCD write failure: DP_LANE_COUNT_SET. - DPCD write failure: DP_LINK_BW_SET. - Final error: enabling link 0 failed: 15. These errors occur shortly after amdgpu initializes. The 7.0 driver reports Display Core v3.2.369, whereas the working 6.17 driver reports Display Core v3.2.340. Both use DMUB firmware 0x0101002B. DMCUB diagnostic errors also occur on successful 6.17 boots, so these messages alone do not explain the failure. ### Reproduction and recovery On an affected boot: 1. Acer firmware logo and GRUB appear normally. 2. Ubuntu splash screen appears. 3. After amdgpu takes over, the internal display becomes black. 4. The system continues booting. 5. Connecting an HDMI monitor allows access to the SDDM login screen. 6. The internal display remains black while waiting at SDDM, including for more than 30 seconds. 7. After logging into KDE Plasma, the internal display becomes operational. The problem can also be recovered without rebooting by disabling and re- enabling the internal eDP-1 output through KDE Display Configuration. ### Additional observations During the SDDM-to-Plasma transition, the logs show: - SDDM successfully starts its Wayland greeter. - The greeter exits after authentication. - Several DMCUB diagnostic errors appear. - The user KDE Wayland compositor starts immediately afterwards. The internal panel becomes operational after entering the Plasma session. This suggests that a display reconfiguration or modeset during the compositor/session transition may recover the failed eDP connection. This is an observation, not a confirmed explanation. ### Request Could the Ubuntu kernel team investigate this additional affected Barcelo/DCN 2.1 system? The similarities with this report are particularly striking, including the GPU identifier, DMUB firmware, kernel-version comparison and DPCD link failures. I can provide additional kernel logs and test patched or proposed kernels if needed. Thank you. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2171342 Title: [Renoir/Barcelo] Internal eDP panel black after boot on 7.0 (enabling link 0 failed: 15), works on 6.17 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2171342/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
