CachyOS / CachyOS/linux-cachyos

[BUG] Regression in linux-cachyos 6.19.10-1: TB eGPU (Razer Core X + RX 6800 XT) drops off PCIe bus (pciehp Link Down / Card not present). Works on 6.19.6-2.

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#794 2 comments 0 reactions 3 assignees Claimed by @ventureoo View on GitHub
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Description

### Pre-flight checklist

- [x] I have searched existing issues and this is not a duplicate.
- [x] I have read the [Contributing Guidelines](https://github.com/CachyOS/linux-cachyos/blob/master/CONTRIBUTING.md).
- [x] I have verified the issue is reproducible with the latest available CachyOS kernel.

### Upstream / vanilla kernel check

I was unable to test with a vanilla/upstream kernel

### Kernel variant

linux-cachyos (EEVDF, Clang)

### System information (cachyos-bugreport.sh)

```text
.
```

### Manual system information (if cachyos-bugreport.sh is unavailable)

```text
Hardware / System
- Laptop: Framework (Alder Lake-P iGPU present)
- eGPU enclosure: Razer Core X (Thunderbolt 3)
- GPU: AMD RX 6800 XT (Navi 21, PCI ID `1002:73bf`)
- Thunderbolt authorization: `boltctl` shows authorized at 40 Gb/s

Please fill in the following (I can provide exact command outputs if needed):
- Kernel version (`uname -r`): 6.19.10-1
- CPU model: 12th Gen Intel(R) Core(TM) i7-1260P
- GPU model & driver:
- iGPU: Intel Corporation Alder Lake-P Integrated Graphics Controller (rev 0c): i915
- eGPU: AMD RX 6800 XT (Navi 21, `1002:73bf`), driver: amdgpu
- Architecture (e.g., `x86-64`, `x86-64-v3`, `x86-64-v4`, `znver4`): x86_64
- Active SCX scheduler (if any): none
```

### Bug description

After upgrading to `linux-cachyos 6.19.10-1`, my Thunderbolt eGPU becomes unusable. The AMD GPU initializes, then the PCIe hotplug port reports `Link Down` and `Card not present`, followed by `amdgpu: device lost from bus!`. The device ends up unbound (no “Kernel driver in use: amdgpu” in `lspci`).

Downgrading the kernel to `linux-cachyos 6.19.6-2` immediately restores correct behavior.

### Steps to reproduce

1. Connect and authorize Razer Core X eGPU
2. Boot linux-cachyos 6.19.10-1
3. Observe that the external monitor on the eGPU stays black / eGPU disappears

### Expected behavior

lspci -nnk -s 81:00.0 shows Kernel driver in use: amdgpu, eGPU remains present, and Vulkan enumerates the AMD GPU

### Actual behavior

- pciehp: Slot(6): Link Down
- pciehp: Slot(6): Card not present
- amdgpu 0000:81:00.0: device lost from bus!

### Logs / stack traces

```text
1383:Apr 04 11:43:18 cachyos-x8664 kernel: pcieport 0000:00:07.3: pciehp: Slot(6): Link Down
1384:Apr 04 11:43:18 cachyos-x8664 kernel: pcieport 0000:00:07.3: pciehp: Slot(6): Card not present
1398:Apr 04 11:43:18 cachyos-x8664 kernel: amdgpu 0000:81:00.0: amdgpu: amdgpu: finishing device.
1399:Apr 04 11:43:18 cachyos-x8664 kernel: amdgpu 0000:81:00.0: amdgpu: device lost from bus!
...
1421:Apr 04 11:43:19 cachyos-x8664 kernel: amdgpu 0000:81:00.0: amdgpu: device lost from bus!
```

### Additional system information

_No response_

Contributor guide

Open the contributing guide

Assessment

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