Missing Thunderbolt 3 PCI-E atomics support

[Timur Kristóf]

On Thu, 2019-03-14 at 12:30 +0200, Mika Westerberg wrote:
> On Wed, Mar 13, 2019 at 07:09:26PM +0100, Timur Kristóf wrote:
> > Hi,
> 
> 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?
> 
> I don't think it has anything to do with TBT itself. AtomicOps is a
> PCIe
> feature.
> 
> What does 'sudo lspci -vv' show for the ports in question?

Hi Mika,

I know atomics is a PCIe feature, but in this case the PCIe goes
through TB3, so I would assume it has something to do with it.

Here is the output of 'lspci -vv':
https://pastebin.com/Qt5RUFVc

Best regards,
Tim