On Oct 2, 2025, at 12:22, Mark Millard <[email protected]> wrote:
> On Oct 2, 2025, at 10:25, Alexander Ziaee <[email protected]> wrote:
>
>> On 2025-10-02 12:47 -04:00 EDT, "Mark Millard" <[email protected]> wrote:
>>> Alexander Ziaee <ziaee_at_FreeBSD.org> wrote on
>>> Date: Thu, 02 Oct 2025 15:14:07 UTC :
>>>
>>>> The branch main has been updated by ziaee:
>>>>
>>>> URL:
>>>> https://cgit.FreeBSD.org/src/commit/?id=2f7a796b590e67c5d123f2b00b3aaf7ba7a32a13
>>>>
>>>> commit 2f7a796b590e67c5d123f2b00b3aaf7ba7a32a13
>>>> Author: Alexander Ziaee <[email protected]>
>>>> AuthorDate: 2025-10-02 12:05:25 +0000
>>>> Commit: Alexander Ziaee <[email protected]>
>>>> CommitDate: 2025-10-02 15:12:48 +0000
>>>>
>>>> thunderbolt.4: Initial manual for HW Relnotes
>>>>
>>>> This manual contains nothing and is only suitable for the HW Relnotes,
>>>> but lets get it in so we have something and then can iterate on it.
>>>>
>>>> MFC after: 3 minutes
>>>> Fixes: 2ed9833791f2 (thunderbolt: Import USB4 code)
>>>> Discussed with: obiwac
>>>> Differential Revision: https://reviews.freebsd.org/D52847
>>>> ---
>>>> share/man/man4/Makefile | 1 +
>>>> share/man/man4/thunderbolt.4 | 22 ++++++++++++++++++++++
>>>> 2 files changed, 23 insertions(+)
>>>>
>>>> diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
>>>> index f5d7a0e081fc..6e076722c786 100644
>>>> --- a/share/man/man4/Makefile
>>>> +++ b/share/man/man4/Makefile
>>>> @@ -589,6 +589,7 @@ MAN= aac.4 \
>>>> tdfx.4 \
>>>> termios.4 \
>>>> textdump.4 \
>>>> + thunderbolt.4 \
>>>> ti.4 \
>>>> timecounters.4 \
>>>> tmpfs.4 \
>>>> diff --git a/share/man/man4/thunderbolt.4 b/share/man/man4/thunderbolt.4
>>>> new file mode 100644
>>>> index 000000000000..3477c11fb60d
>>>> --- /dev/null
>>>> +++ b/share/man/man4/thunderbolt.4
>>>> @@ -0,0 +1,22 @@
>>>> +.\"
>>>> +.\" Copyright (c) 2025 Alexander Ziaee
>>>> +.\"
>>>> +.\" SPDX-License-Identifier: BSD-2-Clause
>>>> +.\"
>>>> +.Dd October 2, 2025
>>>> +.Dt THUNDERBOLT 4
>>>> +.Os
>>>> +.Sh NAME
>>>> +.Nm thunderbolt
>>>> +.Nd USB4 controller driver
>>>> +.Sh SYNOPSIS
>>>> +.Cd device thunderbolt
>>>> +.Sh HARDWARE
>>>> +The
>>>> +.Nm
>>>> +driver supports USB4 controllers.
>>>
>>> As I understand things, being fairly explicit related the
>>> following is likely required (not a proposed wording or
>>> presentation):
>>>
>>> Quoting USB4 V2: "A USB4 Host or USB4 Peripheral Device can
>>> optionally support interoperability with Thunderbolt 3
>>> (TBT3) products."
>>>
>>> Quoting USB4 V1: "A USB4 host or USB4 peripheral device can
>>> optionally support interoperability with Thunderbolt 3
>>> (TBT3) products."
>>>
>>> In both, this is tied to Chapter 13, "Interoperability with
>>> Thunderbolt(tm) 3 systems". As I understand FreeBSD is not
>>> trying to meet the criteria in that chapter, for example.
>>>
>>> USB4 does not require a certification process, as I
>>> remember. Thunderbolt 4 and 5 do, as I remember.
>>>
>>> As I remember, a distinction between USB4 and Thunderbolt 4
>>> and 5 was that Thunderbolt 4 and 5 require (nearly?) all
>>> optional items from the matching USB4 version to be
>>> implemented (so: not optional if Thunderbolt 4 or 5 is
>>> claimed/certified). Also, it seems unlikely that FreeBSD
>>> would go through a Thunderbolt 4 or 5 certification process.
>>>
>>> Overall this seems to mean not meeting the Thunderbolt 4
>>> and/or 5 criteria fully and not supporting Thunderbolt 3
>>> --but just meeting the criteria for one or both of:
>>>
>>> ) USB4 V1 without "TBT3" support
>>> ) USB4 V2 without "TBT3" support
>>>
>>> That would be a subset of the Thunderbolt 4 or 5 criteria
>>> in a way that excludes Thunderbolt 3.
>>>
>>> Referencing Thunderbolt without someplace being fairly
>>> explicit about those types of relationships could easily
>>> leave a misimpression (even if I've gotten some of the
>>> status wrong above).
>>>
>>> My guess here is that enough is known about the intent
>>> in this area to be able to have material about this type
>>> of thing in place at any time.
>>
>> My impression is that actually nothing works yet, but we now have a driver
>> called thunderbolt which is made to support these controllers. The driver is
>> in, allegedly, and so it's existence needs to be mentioned in the canonical
>> places where we mention our drivers because people are looking for them for
>> assorted reasons.
>
> I've actually booted a Dell Precision 5490 via external
> USB4 media, but only when it was downstream of a Thunderbolt
> 3 hub. All 4 USB ports are USB4 on this 5490. And that was
> some time ago: early 2025-Feb with 1500031 of main 15. It
> saw the USB4 media as nda0 at nvme0 .
>
> This only works as much as it does because the UEFI/ACPI
> involved supports enough to make some things possible
> such that FreeBSD does not need to be as involved.
>
> As I remember, I set up and did some live-plugging/unlugging
> experiments any they lead to panics. The configuration had
> to be as it was at boot time. If I remember right this
> looked like Thunderbolt 3 mishandling (no surprise).
>
> Directly connected, the transition from the kernel to
> the world/root mount for the USB4 media fails instead.
>
> I've not yet tried updating the USB4 media with a more
> recent FreeBSD main 16 to see what happens now.
I updated the USB4 boot media to be based on:
# uname -apKU
FreeBSD USB4sys 16.0-CURRENT FreeBSD 16.0-CURRENT main-n280801-213170eb956f
GENERIC-NODEBUG amd64 amd64 1600001 1600001
(It is from official pkgbase distribution use, a
copy of another boot media with some parameters
replaced afterwards.)
I tried it and the system booted --via the USB4
media being "da0":
# gpart show -p
=> 34 500118125 nda0 GPT (238G)
34 2014 - free - (1.0M)
2048 1925120 nda0p1 efi (940M)
1927168 25165824 nda0p2 ms-reserved (12G)
27092992 473024512 nda0p3 linux-data (226G)
500117504 655 - free - (328K)
=> 40 3907029088 da0 GPT (1.8T)
40 409600 da0p1 efi (200M)
409640 3638558720 da0p2 freebsd-ufs (1.7T)
3638968360 251658240 da0p3 freebsd-swap (120G)
3890626600 16402528 - free - (7.8G)
No external hub involved.
(As before, the external USB Ethernet plugged into
one of the USB4 ports works too.)
(The internal nvme showing up as nda0 has a
ubuntu installation on it, as distributed
by Dell.)
I've only done basic boot testing and minimal
use after that. Some basic testing of plugging
and unplugging Thunderbolt 3 media did not lead
to any crashes. This was both via a USB4 port
and via the Thunderbolt 3 hub. An example for
a USB4 port produced:
pci12: <PCI bus> on pcib8
pcib17: <PCI-PCI bridge> at device 0.0 on pci12
pcib17: failed to allocate initial I/O port window: 0-0xfff
pcib17: failed to allocate initial memory window: 0-0xfffff
pcib17: failed to allocate initial prefetch window: 0-0xfffff
pci13: <PCI bus> on pcib17
pcib18: <PCI-PCI bridge> at device 1.0 on pci13
pcib18: failed to allocate initial I/O port window: 0-0xfff
pcib18: failed to allocate initial memory window: 0-0xfffff
pcib18: failed to allocate initial prefetch window: 0-0xfffff
pci14: <PCI bus> on pcib18
pcib19: <PCI-PCI bridge> at device 2.0 on pci13
pcib19: failed to allocate initial I/O port window: 0-0xfff
pcib19: failed to allocate initial memory window: 0-0xfffff
pcib19: failed to allocate initial prefetch window: 0-0xfffff
pci15: <PCI bus> on pcib19
xhci2: <Intel Titan Ridge Thunderbolt 3 USB controller> mem
0x73e00000-0x73e0ffff at device 0.0 on pci15
xhci2: 32 bytes context size, 64-bit DMA
xhci2: xECP capabilities
<PROTO,VEND(c0),LEGACY,VEND(c6),VEND(c7),VEND(c2),DEBUG,VEND(c3),VEND(c4),VEND(c5),VEND(c8),VEND(c9),PROTO,VEND(ca)>
usbus2 on xhci2
usbus2: 5.0Gbps Super Speed USB v3.0
pcib20: <PCI-PCI bridge> at device 4.0 on pci13
pcib20: failed to allocate initial I/O port window: 0-0xfff
pcib20: failed to allocate initial memory window: 0-0xfffff
pcib20: failed to allocate initial prefetch window: 0-0xfffff
ugen2.1: <Intel XHCI root HUB> at usbus2
uhub6 on usbus2
uhub6: <Intel XHCI root HUB, class 9/0, rev 3.00/1.00, addr 1> on usbus2
uhub6: 4 ports with 4 removable, self powered
pcib20: detached
uhub6: detached
ugen2.1: <Intel XHCI root HUB> at usbus2 (disconnected)
unknown: at usbus2, port 1, addr 1 (disconnected)
usbus2: detached
xhci2: Controller reset timeout.
xhci2: detached
pci15: detached
pcib19: detached
pci14: detached
pcib18: detached
pci13: detached
pcib17: detached
pci12: detached
FYI:
CPU: Intel(R) Core(TM) Ultra 7 165H (3072.00-MHz K8-class CPU)
Origin="GenuineIntel" Id=0xa06a4 Family=0x6 Model=0xaa Stepping=4
. . .
WARNING: L3 data cache covers more APIC IDs than a package (6 > 3)
FreeBSD/SMP: Multiprocessor System Detected: 22 CPUs
FreeBSD/SMP: Non-uniform topology
# dmesg -a | grep "no driver attached"
pci0: <multimedia> at device 5.0 (no driver attached)
pci1: <network> at device 0.0 (no driver attached)
pci0: <unknown> at device 11.0 (no driver attached)
pci0: <serial bus, USB> at device 13.2 (no driver attached)
pci0: <serial bus, USB> at device 13.3 (no driver attached)
pci0: <simple comms, UART> at device 18.0 (no driver attached)
pci0: <memory, RAM> at device 20.2 (no driver attached)
pci0: <serial bus> at device 21.0 (no driver attached)
pci0: <serial bus> at device 21.3 (no driver attached)
pci0: <simple comms> at device 22.0 (no driver attached)
pci4: <unknown> at device 0.0 (no driver attached)
pci0: <serial bus> at device 31.5 (no driver attached)
>> Patches to the doc are extremely welcome!
>
> I'd need a lot more certainty about interpreting the
> more informal references that are around vs. the
> terminology in the USB4 specifications (or other
> such).
>
> I've been more trying to point out subject areas than
> knowing for sure the details that I used for
> illustration.
>
>> Best,
>> Alex
>>
>>>> +.Sh HISTORY
>>>> +The
>>>> +.Nm
>>>> +driver appeared in
>>>> +.Fx 15.0 .
>>>>
>>>
>>> ===
>>> Mark Millard
>>> marklmi at yahoo.com
===
Mark Millard
marklmi at yahoo.com
