ASUS TUF A16 - RX 7600S falls off the bus after 8bd82363e2ee

On my ASUS TUF A16 laptop, the dGPU (an RX 7600S) will occasionally fall off the bus - that is, the pcieport driver complains about a broken device/link:

kernel: pcieport 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s
kernel: pcieport 0000:00:01.1: retraining failed
kernel: pcieport 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s
kernel: pcieport 0000:00:01.1: retraining failed
kernel: pcieport 0000:01:00.0: not ready 1023ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 2047ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 4095ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 8191ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 16383ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 32767ms after resume; waiting
kernel: pcieport 0000:01:00.0: not ready 65535ms after resume; giving up
kernel: pcieport 0000:00:01.1: pciehp: Slot(0): Card not present
kernel: pcieport 0000:01:00.0: Unable to change power state from D3cold to D0, device inaccessible
kernel: pcieport 0000:02:00.0: Unable to change power state from D3cold to D0, device inaccessible
kernel: amdgpu 0000:03:00.0: Unable to change power state from D3cold to D0, device inaccessible
kernel: [drm:gmc_v11_0_flush_gpu_tlb [amdgpu]] *ERROR* Timeout waiting for sem acquire in VM flush!
kernel: amdgpu 0000:03:00.0: amdgpu: Timeout waiting for VM flush ACK!
kernel: [drm:gmc_v11_0_flush_gpu_tlb [amdgpu]] *ERROR* Timeout waiting for sem acquire in VM flush!
kernel: amdgpu 0000:03:00.0: amdgpu: Timeout waiting for VM flush ACK!

This is followed by amdgpu trying to gracefully shut down the device, causing a slew of WARNs by various cleanup functions that assume there is still a GPU to clean up.

Bisecting this led to 8bd82363e2ee ("drm/amdgpu: revert "take runtime pm reference when we attach a buffer" v2") being the first bad commit.

The commit itself looks sensible/correct - I suspect it merely exposes some underlying problem with GPU/PCI power management on the platform, though I have no idea how I'd debug this/which information is necessary.

It's also curious that the "non-functional downstream link" message comes from a PCI bridge device (see lspci output for the involved devices) as opposed to the actual GPU:

00:01.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h-19h PCIe GPP Bridge (prog-if 00 [Normal decode])
        Subsystem: ASUSTeK Computer Inc. Device 1513
        Flags: bus master, fast devsel, latency 0, IRQ 33, IOMMU group 1
        Bus: primary=00, secondary=01, subordinate=03, sec-latency=0
        I/O behind bridge: f000-ffff [size=4K] [16-bit]
        Memory behind bridge: fcb00000-fcdfffff [size=3M] [32-bit]
        Prefetchable memory behind bridge: 7c00000000-7e0fffffff [size=8448M] [32-bit]
        Capabilities: <access denied>
        Kernel driver in use: pcieport

01:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Upstream Port of PCI Express Switch (rev 12) (prog-if 00 [Normal decode])
        Physical Slot: 0
        Flags: bus master, fast devsel, latency 0, IRQ 39, IOMMU group 13
        Memory at fcd00000 (32-bit, non-prefetchable) [size=16K]
        Bus: primary=01, secondary=02, subordinate=03, sec-latency=0
        I/O behind bridge: f000-ffff [size=4K] [16-bit]
        Memory behind bridge: fcb00000-fccfffff [size=2M] [32-bit]
        Prefetchable memory behind bridge: 7c00000000-7e0fffffff [size=8448M] [32-bit]
        Capabilities: <access denied>
        Kernel driver in use: pcieport

02:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Downstream Port of PCI Express Switch (rev 12) (prog-if 00 [Normal decode])
        Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Downstream Port of PCI Express Switch
        Flags: bus master, fast devsel, latency 0, IRQ 40, IOMMU group 14
        Bus: primary=02, secondary=03, subordinate=03, sec-latency=0
        I/O behind bridge: f000-ffff [size=4K] [16-bit]
        Memory behind bridge: fcb00000-fccfffff [size=2M] [32-bit]
        Prefetchable memory behind bridge: 7c00000000-7e0fffffff [size=8448M] [32-bit]
        Capabilities: <access denied>
        Kernel driver in use: pcieport

03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 33 [Radeon RX 7600/7600 XT/7600M XT/7600S/7700S / PRO W7600] (rev c3) (prog-if 00 [VGA controller])
        Subsystem: ASUSTeK Computer Inc. Device 231d
        Flags: bus master, fast devsel, latency 0, IRQ 68, IOMMU group 15
        Memory at 7c00000000 (64-bit, prefetchable) [size=8G]
        Memory at 7e00000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=256]
        Memory at fcb00000 (32-bit, non-prefetchable) [size=1M]
        Expansion ROM at fcc00000 [disabled] [size=128K]
        Capabilities: <access denied>
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu

Let me know if there is any other helpful info I could provide.