Title: REG_WAIT timeout in optc3x_disable_crtc at first modeset on both Raphael iGPU and RX 7600 (MSI PRO B650-P WIFI, HDMI) - display stays black
Summary With nomodeset removed, amdgpu initializes both GPUs but logs a REG_WAIT timeout in optc*_disable_crtc, and the display stays black while the system keeps running (commands run over SSH during the black screen). The same failure occurs on two different GPUs on the same board and monitor: the Ryzen's Raphael iGPU and a Navi 33 card. With nomodeset the system is stable on the firmware framebuffer. Hardware - Board: MSI PRO B650-P WIFI (MS-7D78), BIOS E7D78AMS.1I0 (03/12/2025) - CPU: AMD Ryzen 9 7900X (Raphael iGPU, 0000:12:00.0) - GPU: ASRock Radeon RX 7600 Challenger OC (Navi 33, 0000:03:00.0) - Display: Viotek 2560x1440 monitor on HDMI only (EDID vendor VTK, product 12800) - BIOS: Re-Size BAR enabled, Above 4G enabled, SR-IOV disabled, Integrated Graphics UMA Auto, HybridGraphics disabled, Secure Boot enabled, Initiate Graphic Adapter [confirm: PEG or IGD for the iGPU boot] Software - Ubuntu 24.04.5 LTS, kernel 6.17.0-40-generic (HWE), X11 session (Wayland disabled in GDM) - amdgpu-dkms 6.16.13 (out-of-tree, from AMD's amdgpu-install, 30.30.1) - /etc/modprobe.d/amdgpu.conf: options amdgpu sg_display=0 gfx_off=0 runpm=0 (gfx_off is reported as an unknown parameter and ignored) Reproduction 1. Boot with kernel command line: ro quiet splash (no nomodeset). 2. amdgpu loads; VBIOS, PSP and DMUB firmware initialize without errors. 3. On the first modeset the timeout below is logged and the display goes black. Logs, iGPU (monitor on the motherboard HDMI) ``` amdgpu 0000:12:00.0: amdgpu: [drm] DMUB hardware initialized: version=0x05002000 amdgpu 0000:12:00.0: amdgpu: runtime pm is manually disabled amdgpu 0000:12:00.0: [drm] fb0: amdgpudrmfb frame buffer device amdgpu 0000:12:00.0: amdgpu: [drm] REG_WAIT timeout 1us * 100000 tries - optc31_disable_crtc line:145 ``` No further messages from 0000:12:00.0 follow. Logs, RX 7600 (monitor on the card's HDMI) ``` amdgpu 0000:03:00.0: amdgpu: [drm] Loading DMUB firmware via PSP: version=0x07002D00 amdgpu 0000:03:00.0: amdgpu: [drm] REG_WAIT timeout 1us * 150000 tries - optc32_disable_crtc line:195 (logged twice) ``` Tried with no change - amdgpu.aspm=0, runpm=0 and sg_display=0 - dc=0 and dpm=0 (in an earlier attempt) - Ubuntu 26.04.1 live image (kernel 7.0, Mesa 26.0.x, in-tree amdgpu), RX 7600 on HDMI: no desktop (cursor only by default; solid white screen with amdgpu.aspm=0 amdgpu.runpm=0). I captured no logs from those boots. Other notes - ASRock support told me they reproduced a similar failure on an MSI PRO B650M-A WIFI with a Ryzen 7 7800X3D, but not on their own Z790 Taichi, B650E Taichi or A620M-HDV/M.2 boards. - Both GPUs fail at the same step on the same board and monitor. I have no second display to test, so I can't rule out the monitor or HDMI link. - Launchpad bug (Ubuntu kernel): https://bugs.launchpad.net/ubuntu/+source/linux-hwe-6.17/+bug/2150485 Questions - Is this a known issue with optc31/optc32 disable_crtc timeouts at first modeset? - Which debug options (drm.debug bits, dcdebugmask) would be most useful? I can test patches or parameters and capture logs over SSH. Full kernel logs (journalctl -b -k) of both failing boots are attached. ** Attachment added: "amdgpu-logs.txt" https://bugs.launchpad.net/ubuntu/+source/linux-hwe-6.17/+bug/2150485/+attachment/6009485/+files/amdgpu-logs.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2150485 Title: amdgpu: REG_WAIT timeout and display blackout on RX 7600 (Navi 33) with kernel 6.17 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-hwe-6.17/+bug/2150485/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
