Re: USB4/TBT3 support [related side note?]

Hi Mark!

On Sun, Dec 22, 2024 at 11:56 PM Mark Millard <marklmi@yahoo.com> wrote:

> Mohammad Noureldin <mohammad_at_thelightbird.com> wrote on
> Date: Fri, 20 Dec 2024 16:04:20 UTC
>
> > . . .
>
> This is more a note about a context that may in some ways be somewhat
> analogous, despite TBT3+ and USB4+ not being involved.
>
> The example that I have access to is a Windows DevKit 2023. It has
> 3 USB-A ports and 2 USB-C ports. FreeBSD works with the USB-A ones
> but not with the USB-C ones. (The FreeBSD loader work for all --via
> the UEFI/ACPI, of course.)
>
> What seems to be unique that might contribute is that the 2 USB-C
> ports also support HBR3 Transmission Mode (4 lane x 8.1 Gbps/lane)
> that has support for:
>
> SST: 5120x2880 @ 60Hz,
> SST: 4096x2160 @ 60Hz,
> MST: (x2) 3840x2160 @ 60Hz (RB2),
> MST: (x2) 2560x1600 @ 60Hz (CVT, RB)
>
> (Not that I use the USB-C ports at all. I stick to the USB-A
> USB ports.)
>
> I'm not proposing that you make the Windows DevKit 2023 USB-C
> ports work. I just do not not know how common such a combination
> is for USB-C. It may be more of an aarch64 specific combination
> rather than anything generalizing much to amd64.
>
> The Windows DevKit 2023 also has a mDP HBR2 port that I do use.
>
> ===
> Mark Millard
> marklmi at yahoo.com
>
>
I also can't judge if this would be (directly) related or not, so I will be
taking a not of it but maybe discuss it over another generally USB related
topic/thread.

That said, I've took part in the discussion with you and @Flox (floxent)
over FreeBSD Kernel Discord Channel and have been trying to test our
assumptions with some of the machines I have, but no success to reproduce
any of the reported issues.

I am intending to text you and @Flox once I can find any new clues.

Thanks Mark and happy holidays 👊

-- 
Thanks
- Mohammad Noureldin
--
"Life is like riding a bicycle. To keep your balance you must keep moving"
- Albert Einstein