Hi everyone,
Posting to bring attention to a kernel 7.2.5 regression affecting AMD Rembrandt/YELLOW_CARP APUs (Ryzen 6000-series / Radeon 680M, e.g., Minisforum UM690, Bosgame EffiZen).
Problem
Upgrading to kernel 7.2.5 breaks secondary display outputs (specifically HDMI). The driver fails to load/initialize the DMCUB firmware, cascading into constant EDID CEA parser errors and display initialization timeouts:
amdgpu 0000:e4:00.0: [drm] *ERROR* dc_dmub_srv_log_diagnostic_data: DMCUB error - collecting diagnostic data
amdgpu 0000:e4:00.0: [drm] REG_WAIT timeout 1us * 100 tries - dcn31_program_compbuf_size line:142
amdgpu 0000:e4:00.0: [drm] *ERROR* EDID CEA parser failed
In my case booting back into kernel 7.1.13 immediately resolves the issue and restores full dual-monitor output.
Bug Tracking & Upstream Patch
- Red Hat Bugzilla: 2532853 – [amdgpu] DMCUB firmware fails to load on kernel 7.2.5-200.fc44 (Ryzen 6800H / Radeon 680M "Rembrandt"/YELLOW_CARP), causing pageflip timeouts and a blank second monitor
- GitLab Issue: Making sure you're not a bot!
AMD engineers have already published a fix patch upstream on linux-graphics:
Could the Fedora kernel maintainers consider backporting this patch into an upcoming 7.2.x build?
Thanks!