Messages in this thread | | | Date | Wed, 5 Sep 2018 16:34:50 +0300 | From | Mika Westerberg <> | Subject | Re: USB type-C altmode support for UCSI |
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On Wed, Sep 05, 2018 at 04:24:29PM +0300, Heikki Krogerus wrote: > +Mika, Mario, LKML > > On Mon, Sep 03, 2018 at 02:17:46PM +0000, whitequark wrote: > > After looking through LKML, I've seen that people refer to you when > > discussing issues with USB-C device compatibility. Do you think you > > could help me with an Apple Thunderbolt 2 to 3 adapter? I've spent > > quite a while studying USB-C, reverse engineering platform and > > adapter firmware and so on, and I'm quite stumped. > > > > I have a Dell XPS13 laptop. UCSI advertises port altmodes > > 8087:00000001, ff01:00001c46, 413c:00000001, in that order. > > When I plug in the adapter, UCSI advertises partner altmode > > 8087:00000001. A billboard class device enumerates. Nothing else > > happens; the Thunderbolt NHI device doesn't appear, and if I force > > it to appear via the WMI hook, there are no Thunderbolt events, > > and the only device on the Thunderbolt bus is the root switch.
Some Dell XPS systems do not support that TBT2<->TBT3 adapter. I think I tried this on XPS 15 9550 and XPS 13 9365 and in both cases it is rejected. I think it has something to do with the PD controller firmware. Same goes if you Plug TB16 dock and to that dock then connect the adapter + device.
Mario probably has more input about this one.
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