Nouveau - Feb 2022 - [PATCH v5 3/7] PCI: Drop the `is_thunderbolt` attribute from PCI core

On Mon, Feb 28, 2022 at 03:33:13PM +0000, Limonciello, Mario
wrote:
> [AMD Official Use Only]
> 
> > 
> > On Fri, Feb 25, 2022 at 11:42:24AM -0600, Bjorn Helgaas wrote:
> > > That would just leave the "PCI_VSEC_ID_INTEL_TBT implies
external-
> > facing"
> > > assumption above.  Not having a Thunderbolt spec, I have no idea
how
> > > you deal with that.
> > 
> > You can download the spec here:
> > 
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww
> > w.usb.org%2Fsites%2Fdefault%2Ffiles%2FUSB4%2520Specification%2520202
> > 11116.zip&data=04%7C01%7Cmario.limonciello%40amd.com%7Ca26e64
> > 7a4acf4e7681d308d9faa358fd%7C3dd8961fe4884e608e11a82d994e183d%7C0
> > %7C0%7C637816402472428689%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC
> > 4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&
> > amp;sdata=HSDqx%2BHzSnczTZxaBij8sgqvJSS8ajtjCzZd2CPSbR4%3D&re
> > served=0
> > 
> > Inside the archive there is also the DVSEC spec with name "USB4
DVSEC
> > Version 1.0.pdf".
> 
> The spec has Host_Router_indication (bits 18-19) as meaning external
facing.
> I'll respin the patch 3 for using that.
Thanks, please include the spec citation when you do.  And probably
the URL, because it's not at all obvious how the casual reader would
get from "is_thunderbolt" to a recent add-on to the USB4 spec.

Bjorn

On Mon, Feb 28, 2022 at 04:13:44PM -0600, Bjorn Helgaas
wrote:
> On Mon, Feb 28, 2022 at 03:33:13PM +0000, Limonciello, Mario wrote:
> > > On Fri, Feb 25, 2022 at 11:42:24AM -0600, Bjorn Helgaas wrote:
> > > > That would just leave the "PCI_VSEC_ID_INTEL_TBT
implies external-
> > > facing"
> > > > assumption above.  Not having a Thunderbolt spec, I have no
idea how
> > > > you deal with that.
> > > 
> > > You can download the spec here:
[...]
> > > Inside the archive there is also the DVSEC spec with name
"USB4 DVSEC
> > > Version 1.0.pdf".
> > 
> > The spec has Host_Router_indication (bits 18-19) as meaning external
facing.
> > I'll respin the patch 3 for using that.
> 
> Thanks, please include the spec citation when you do.  And probably
> the URL, because it's not at all obvious how the casual reader would
> get from "is_thunderbolt" to a recent add-on to the USB4 spec.
PCI_VSEC_ID_INTEL_TBT is not mentioned at all in the USB4 spec,
hence there's no connection between "is_thunderbolt" and the USB4
spec.

It's a proprietary VSEC used by Intel and the only way to recognize
pre-USB4 Thunderbolt devices that I know of.  Its ID is also
different from the DVSEC IDs given in the above-mentioned spec.

Thanks,

Lukas