Hi, System information: - Model: Lenovo ThinkPad X13 Gen 4 (21J3SITM18) - BIOS: R29ET65W (1.39) - Kernel: 7.0.0-28-generic (Ubuntu 24.04) - GPU: AMD/ATI Phoenix1 [1002:15bf] (rev de) — Radeon 780M
Current workaround: Kernel parameter amdgpu.dcdebugmask=0x10 is required for clean shutdown. Without it, the system goes through the full shutdown sequence (poweroff.target reached, filesystems synced, SIGTERM sent), but then pm_power_off() hangs — screen goes black but power stays on indefinitely. With amdgpu.dcdebugmask=0x10 (DC_DBG_MASK_DC bit 4), shutdown works normally. Similarly, reboot also hangs with the default EFI reset method and requires reboot=kbd as a workaround. Kernel command line without workaround (shutdown hangs): acpi=force no_console_suspend ignore_loglevel Kernel command line with workaround (shutdown works): acpi=force no_console_suspend ignore_loglevel amdgpu.dcdebugmask=0x10 The issue is 100% reproducible — every shutdown without the debug mask hangs. A DMI quirk for this model would be appreciated so the mask is applied automatically. Let me know if you need any additional debug information. Thanks, nie
