Same here — another data point with an RX 6800 XT.
I’m hitting the exact same behavior on 7.1.1-2-cachyos: normal operation is fine, but on both reboot and shutdown the system unmounts everything cleanly and then hangs — power LED and case/GPU fans stay on, no POST, monitors stay off. Only a forced power-off via the case button gets me out. Booting the LTS kernel (6.18.36-1) makes the problem disappear completely — every reboot/shutdown works.
The last thing written to the persistent journal is always the journal flush stopping (right after the final unmounts), so the hang happens in the very last systemd-shutdown / kernel poweroff phase, after journald is already gone — nothing useful gets logged to disk.
My setup:
- GPU: AMD Radeon RX 6800 XT (Navi 21, 1002:73bf)
- CPU: Ryzen 7 5800X3D
- Board / BIOS: ASUS ROG STRIX B550-F GAMING, BIOS 3611 (2024-09-29)
- Kernel (broken): linux-cachyos 7.1.1-2
- Kernel (works): linux-cachyos-lts 6.18.36-1
- mesa: 3:26.1.2-1
- Root FS: btrfs · Bootloader: Limine 12.3.3 · DE: KDE Plasma (Wayland)
This matches the other report in this thread (RX 6950 XT, btrfs, Limine), so it looks like a non-LTS 7.1.x amdgpu regression affecting RX 6000-series cards rather than a board-specific issue. Happy to test patches or grab additional logs (e.g. via systemd.log_level=debug or a debug-shell on shutdown) if that helps narrow it down.