Message-ID: <17ed42fe-9d8d-46da-8434-f508ec5932fa@kernel.org>
Date: Thu, 7 Aug 2025 11:07:39 -0500
From: Mario Limonciello <superm1@...nel.org>
To: Greg KH <gregkh@...uxfoundation.org>,
 Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc: "Rangoju, Raju" <raju.rangoju@....com>, linux-usb@...r.kernel.org,
 linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
 andreas.noever@...il.com, michael.jamet@...el.com, westeri@...nel.org,
 YehezkelShB@...il.com, bhelgaas@...gle.com, Sanath.S@....com
Subject: Re: [PATCH 0/3] thunderbolt: Update XDomain vendor properties
 dynamically

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!

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