Arch Linux

Fyubi

Member

Registered: 2025-10-30

Posts: 1

Nvidia eGPU [nvidia-drm] Failed to allocate NvKmsKapiDevice

Hi, I’m trying to get an external GTX 1080 Ti working through an EXP GDC dock connected via the mPCIe port (where the wifi card used to be) on Arch Linux, but I’m stuck at initialization. I previously got it working in Win 10 and 11 and used it for about 2 years, but due to the stuff going with Win11 + many annoying glitches Win11 was throwing me since I had to bypass the Win11 requirements since my CPU (Intel i7-4910mq 3.9GHz) wasn't supported. So since I already had a bit of knowledge about Linux in the past and knew that I wouldn't have problems with error12/DSDT override like I had on Win, I decided to switch.
So anyway, the system detects the GPU, but `nvidia-smi` can’t see it, and `dmesg` throws:

[drm:nv_drm_dev_load [nvidia_drm]] *ERROR* [nvidia-drm] [GPU ID 0x00000200] Failed to allocate NvKmsKapiDevice

NVRM: GPU 0000:02:00.0: RmInitAdapter failed! (0x24:0x72:1590)

Hardware info:

* GPU: GTX 1080 Ti FE 11GB
* Dock: EXP GDC via mPCIe
* Power: external PSU (450W stable)
* System: Arch Linux (up to date, kernel `Linux 6.17.5-2-cachyos`)
* NVIDIA driver: `nvidia 580.95.05` (proprietary)
* Secure Boot: disabled
* eGPU setup handled via custom GRUB entry (for detection and port retrain)

The GPU is detected fine with `lspci`:

02:00.0 VGA compatible controller: NVIDIA Corporation GP102 [GeForce GTX 1080 Ti] (rev a1)
        Kernel driver in use: nvidia
        Kernel modules: nouveau, nvidia_drm, nvidia

And BAR allocation looks normal:

Region 0: Memory at fd000000 (32-bit, non-prefetchable) [size=16M]
Region 1: Memory at e00000000 (64-bit, prefetchable) [size=256M]
Region 3: Memory at dfe000000 (64-bit, prefetchable) [size=32M]
Region 5: I/O ports at 2000 [size=128]

I’ve tried:
* `pci=noaer` and `pci=nocrs` kernel params;
* disabling `nvidia-drm.modeset=1` ;
* using the open kernel driver (incompatible with Pascal cards);
* using the nouveau kernel driver ;
* using older kernel drivers;
* looking around for other similar cases and using their fixes.
But no luck.

NOTE: to bypass the whitelist of the mPCIe port, I use a script before boot, which also retrains the mPCIe link to Gen2 (5.0 GT/s) and performs 56.25GB 36-bit PCI compaction, same as I did on Win10/11, and it works flawlessly.

I need the GPU for gaming and projects, worked perfectly before and haven't had trouble with it, neither too much performance losseven on newer games.
Don't have any money, planning to buy something newer but cheap which would probably fix it by being able to use nvidia-open drivers, but I really can't afford it for now.
Any help or ideas would be much appreciated, I've been struggling at this for over a week.

P.S. most of the parts costed me no money, the laptop was earned, the GPU was gifted by a friend, and the rest like the USB wifi adpter, PSU and dock sum to around 100$.

Edit: thought it would be important to notice that on Win, every time after reinstalling the drivers (tested with multiple drivers to find the best one) I always had to use the nvidia-error43-fixer to get rid of error43, otherwise it would not work.

Last edited by Fyubi (2025-10-30 22:21:40)