Using a Radeon RX 6800 with Ampere with Linux

Hello, I plan on converting my desktop from an x86 system to an Ampere system. I would like to save costs and use my existing Radeon RX 6800. I am wondering if anyone has attempted to get it working under Linux. I cannot work under Windows as I need Linux to be able to do OS development and compile LLVM for Linux using the Nix package manager. The reason why I want to have a graphics card is so that I could try GPU accelerated games, even if they don’t work I can look into trying to fix them for the distro I use. I heard from Jeff Geerling that Radeon card don’t quite work and the documentation only lists NVIDIA cards. The problem with going to NVIDIA is then I have to rely on proprietary drivers and there’s the Wayland issue.


As far as I’m aware, the issue preventing use of AMD graphics cards is the PCIe errata on the Altra SoCs.
If you have the ability to apply a patch to the kernel and rebuild, there’s a patch to work around it.

Patching isn’t a problem. Is there already a patch that I can apply?

Yes there is!
See GitHub - AmpereComputing/linux-ampere-altra-erratum-pcie-65: Kernel patches with workaround for Altra erratum PCIE_65

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Amazing, I’ll try it out once I have an Ampere system.

Are those patches on a way to mainline?

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Unfortunately not. Ampere isn’t going to provide any support for them, and they’re provided as a POC.

We have provided a proof-of-concept software patch under the GPL v2 that will allow
experimental and development work to proceed. PER THE TERMS OF THAT LICENSE



So Altra PCIe controller is b0rken, Ampere has some fix to get cards working but blame whoever else instead of fixing it in mainline?

I am thinking of spending almost 3k€ on new workstation. The biggest computer-related expense in my life. And just got hit with info that if I want to use my RX 6700XT card then I need to carry two kernel patches and rebuild distro kernel again and again and again…

Maybe Xeon is not that bad alternative.

The performance of Ampere probably isn’t that bad so having to build the Linux kernel isn’t that big of a deal. In my case, I’m going to be using NixOS on it so when I build an update, it’ll rebuild the kernel if needed.

I understand that there are people who like to build kernel and those who like to build whole distribution for their machine.

But that’s not me. I was building whole distributions for embedded targets 10+ years ago. Nowadays I rely on repositories to provide me ready to use binary packages. Never mind is it Debian, Fedora, OpenWRT or other.

Especially when external patches are involved. Especially++ when they are not maintained and needs to be refreshed by me.