Re: [PATCH 0/3] thunderbolt: Update XDomain vendor properties dynamically

From: Mika Westerberg
Date: Fri Aug 08 2025 - 00:45:59 EST


On Thu, Aug 07, 2025 at 11:07:39AM -0500, Mario Limonciello wrote:
> On 8/7/25 11:02 AM, Greg KH wrote:
> > On Thu, Aug 07, 2025 at 07:15:33AM +0200, Mika Westerberg wrote:
> > > On Wed, Aug 06, 2025 at 05:58:26PM +0100, Greg KH wrote:
> > > > On Wed, Aug 06, 2025 at 05:00:24PM +0200, Mika Westerberg wrote:
> > > > > On Wed, Aug 06, 2025 at 09:06:30AM -0500, Mario Limonciello wrote:
> > > > > > On 8/6/2025 3:51 AM, Mika Westerberg wrote:
> > > > > > > On Wed, Aug 06, 2025 at 11:46:04AM +0530, Rangoju, Raju wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > On 7/28/2025 12:17 PM, Mika Westerberg wrote:
> > > > > > > > > Hi,
> > > > > > > > >
> > > > > > > > > On Tue, Jul 22, 2025 at 11:20:23PM +0530, Raju Rangoju wrote:
> > > > > > > > > > This patch series aims to update vendor properties for XDomain
> > > > > > > > > > dynamically for vendors like AMD, Intel and ASMedia.
> > > > > > > > >
> > > > > > > > > The XDomain properties pretty much describe "software" not the underlying
> > > > > > > > > hardware so I don't understand why this is needed? We could have some USB
> > > > > > > > > IF registered Linux specific ID there but I don't see why this matters at
> > > > > > > > > all.
> > > > > > > >
> > > > > > > > Currently, it is showing up as "Intel" on AMD host controllers during
> > > > > > > > inter-domain connection. I suppose an alternative is to just call it "Linux"
> > > > > > > > or "Linux Connection Manager" to ensure we accurately represent the
> > > > > > > > connections across different systems.
> > > > > > > >
> > > > > > > > I appreciate your guidance on this and suggestions you might have.
> > > > > > >
> > > > > > > Yeah, something like that (I prefer "Linux"). The "ID" still is 0x8086
> > > > > > > though but I don't think that matters. AFAIK we have other "donated" IDs in
> > > > > > > use in Linux. Let me check on our side if that's okay.
> > > > > >
> > > > > > Having looked through this discussion I personally like "Linux" for this
> > > > > > string too.
> > > > > >
> > > > > > As for the vendor ID doesn't the LF have an ID assigned already of 0x1d6b?
> > > > > > Would it make sense to use that?
> > > > >
> > > > > AFAIK that's PCI ID, right? It should be USB IF assigned ID and LF is not
> > > > > here at least:
> > > > >
> > > > > https://www.usb.org/members
> > > > >
> > > > > If it really matters we can sure register one.
> > > >
> > > > Linux has an official USB vendor id, we use it for when Linux is used as
> > > > a USB gadget device and in a few other places. If you want to reserve a
> > > > product id from it, just let me know and I can dole it out (the list is
> > > > around here somewhere...)
> > >
> > > Yes please :) I think this is the right thing to do.
> >
> > Great, please let me know why you need it and what it will be for and
> > why. I totally can not figure that out from this thread...
> >
> > thanks,
> >
> > greg k-h
>
> Actually it's a very similar reason for the gadget drivers. When connected
> to other machines and using the USB4 networking feature (like a host to host
> communication) the Linux kernel will identify itself and the other side will
> show that to a user.
>
> So right now it's got some hardcoded values. This thread was prompting to
> change the strings, but it's brought about the realization that we should
> also be using a Linux specific vendor (the one uses in gadget devices) and
> then a Linux specific "device id" which you will allocate.
>
> Hope that helps!

Thanks Mario, yes exactly that :)

"Linux USB4 Inter-domain discovery properties" in a nutshell.