Missing Thunderbolt 3 PCI-E atomics support

[Timur Kristóf]

Hi,

I was sent here by Greg KH from the Linux USB mailing list, I hope this
is the right place to ask.

PCI-E atomics don't work for me with Thunderbolt 3.
I see the following message from my Thunderbolt 3 eGPU in dmesg:

kfd: skipped device 1002:67df, PCI rejects atomics

Hardware is a Dell XPS 13 9370 (with i7-8550U CPU) connected to a Zotac
AMP mini, with an AMD RX 570 graphics card. Due to this, I cannot use
the GPU for OpenCL, because the compute stack requires PCI-E atomics
support [1].

What could be the problem? Is this a hardware limitation or a missing
feature in the Linux TB driver?

[1] https://github.com/RadeonOpenCompute/ROCm/issues/157

Thanks & best regards,
Tim

ps. I'm not subscribed to the list, please CC me on your replies.