After installing kernel 5.16 from the Arch Linux repository and booting it up I can no longer get amdgpu to work on my Sea Islands card.

This is the output I get from the kernel:

Jan 14 11:41:43 kyle kernel: Command line: initrd=\amd-ucode.img initrd=\initramfs-linux.img root="LABEL=arch" radeon.cik_support=0 amdgpu.cik_support=1 radeon.si_support=0 amdgpu.si_support=1 amdgpu.dc=1
Jan 14 11:41:43 kyle kernel: Kernel command line: initrd=\amd-ucode.img initrd=\initramfs-linux.img root="LABEL=arch" radeon.cik_support=0 amdgpu.cik_support=1 radeon.si_support=0 amdgpu.si_support=1 amdgpu.dc=1
Jan 14 11:41:43 kyle kernel: ACPI: bus type drm_connector registered
Jan 14 11:41:43 kyle kernel: [drm] amdgpu kernel modesetting enabled.
Jan 14 11:41:43 kyle kernel: amdgpu: Ignoring ACPI CRAT on non-APU system
Jan 14 11:41:43 kyle kernel: amdgpu: Virtual CRAT table created for CPU
Jan 14 11:41:43 kyle kernel: amdgpu: Topology: Add CPU node
Jan 14 11:41:43 kyle kernel: [drm] Unsupported asic.  Remove me when IP discovery init is in place.

Rebooting with kernel 5.15.14 and the same kernel command line arguments works fine.

My card is a Radeon R9 280X (taken on 5.15.14):
09:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Tahiti XT [Radeon HD 7970/8970 OEM / R9 280X] (prog-if 00 [VGA controller])
        Subsystem: ASUSTeK Computer Inc. Tahiti XTL [Radeon R9 280X DirectCU II TOP]
        Flags: bus master, fast devsel, latency 0, IRQ 100, IOMMU group 23
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Memory at fce00000 (64-bit, non-prefetchable) [size=256K]
        I/O ports at e000 [size=256]
        Expansion ROM at fce40000 [disabled] [size=128K]
        Capabilities: [48] Vendor Specific Information: Len=08 <?>
        Capabilities: [50] Power Management version 3
        Capabilities: [58] Express Legacy Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Capabilities: [150] Advanced Error Reporting
        Capabilities: [270] Secondary PCI Express
        Capabilities: [2b0] Address Translation Service (ATS)
        Capabilities: [2c0] Page Request Interface (PRI)
        Capabilities: [2d0] Process Address Space ID (PASID)
        Kernel driver in use: amdgpu
        Kernel modules: radeon, amdgpu

Please let me know if I can add any more information.