Hi, I am currently away on a two week business trip, and I dont have the computer that has problem with me. I will provide you with the requested information as soon as I get back home.
Best regards Joel Ottosson Den sön 25 okt. 2026 kl 18:55 skrev Changwei Zou <[email protected] >: > Thank you very much for reporting this issue. > Could you please provide more information? > Please boot into the Ubuntu kernel and run the following command in a > terminal > to collect debugging information and attach it to this report. > > $ sudo apport-collect 2172124 > > ** Changed in: linux (Ubuntu) > Status: New => Incomplete > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/2172124 > > Title: > [regression] amdgpu: internal eDP panel stays black on 7.0 kernels > ("enabling link 0 failed: 15") – HP OMEN 16-c0xxx, Ryzen 9 5900HX > (Cezanne, DCN 2.1); 6.17 works > > Status in linux package in Ubuntu: > Incomplete > > Bug description: > Hardware > - HP OMEN by HP Laptop 16-c0xxx (SKU 4S1A5EA#UUW, board 8912), BIOS F.19 > (01/09/2023) > - AMD Ryzen 9 5900HX, iGPU Cezanne [1002:1638] (DCN 2.1) drives the > internal eDP panel (2560x1440) > - dGPU NVIDIA RTX 3070 Mobile [10de:249d] (not involved, see below) > - Ubuntu 26.04.1 LTS (upgraded from 24.04) > > Problem > With every 7.0 kernel I have tried, the internal laptop panel stays > black after amdgpu takes over > from the firmware framebuffer. The Ubuntu boot logo is visible > (firmware/simpledrm), then the panel > goes black and never comes back. External monitor works; the GDM login > is placed on the (black) > internal panel. Closing and reopening the lid does not recover it: every > attempt to enable the > panel logs the same error. > > amdgpu 0000:06:00.0: [drm] enabling link 0 failed: 15 > > (15 = link training failure). No other amdgpu errors are printed. > > Kernels > - 6.17.0-22 / -29 / -35 / -40 (Display Core v3.2.340): panel works, 0 > failures in 12+ boots since June 2026 > - 7.0.0-28, 7.0.0-34, 7.0.0-38 (Display Core v3.2.369): panel black on > nearly every boot (16 of 20 boots), first seen with 7.0.0-28 in July 2026 > - Same result with the 24.04 HWE build and the 26.04 build of 7.0.0-38 > > Things ruled out > - NVIDIA driver: fails with > module_blacklist=nvidia,nvidia_drm,nvidia_modeset,nvidia_uvm (attached > dmesg is from that boot; no NVIDIA module loaded) > - External monitor / Dell WD19 dock: fails with everything unplugged > - Firmware: fails with the 24.04 green_sardine firmware placed in > /lib/firmware/updates (DMCUB 0x0101002B is identical in both) > - Boot parameters: fails without crashkernel=, with vt.handoff=7, with > nvidia-drm.fbdev=0, and with amdgpu.dcdebugmask=0x10 (PSR disabled) > > Possibly related > Very similar reports on other Renoir/Cezanne (DCN 2.1) laptops with 7.0 > kernels: > - https://github.com/CachyOS/linux-cachyos/issues/832 – eDP fails to > initialize on 7.0; the reporter traced it to > dmub_srv_wait_for_idle() switching to a progressive backoff, which > makes the 100 ms timeout expire after ~11 ms, > while the eDP panel power-on DMUB command (VBIOS_LVTMA_CONTROL) takes > ~180 ms on that hardware. > - https://github.com/CachyOS/linux-cachyos/issues/831 – same "enabling > link 0 failed: 15" on a Ryzen 7 5825U; fixed in > CachyOS by reverting that change (commit > 0bb166ba01aa1b35765d4af57a9345f73bdf5cec in their tree). > I don't see the DMCUB diagnostic errors from those reports in my log, so > I'm not certain it is the same root cause. > > Workaround > Booting the 24.04 6.17.0-40 kernel. > > Attachments > - dmesg-7.0.0-38-black-panel-nvidia-blocked.txt (failing boot, NVIDIA > blocked) > - dmesg-6.17.0-40-working.txt (same machine, working) > - boot-history.txt (kernel and time of the first eDP link failure for > each boot since May 2026) > - lspci.txt > > I'm happy to test patched or -proposed kernels. > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2172124/+subscriptions > > ** Bug watch added: github.com/CachyOS/linux-cachyos/issues #832 https://github.com/CachyOS/linux-cachyos/issues/832 ** Bug watch added: github.com/CachyOS/linux-cachyos/issues #831 https://github.com/CachyOS/linux-cachyos/issues/831 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2172124 Title: [regression] amdgpu: internal eDP panel stays black on 7.0 kernels ("enabling link 0 failed: 15") – HP OMEN 16-c0xxx, Ryzen 9 5900HX (Cezanne, DCN 2.1); 6.17 works To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2172124/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
