On Thu, Aug 03, 2023 at 03:31:16PM +0000, Simon Ser wrote: > On Thursday, August 3rd, 2023 at 17:22, Simon Ser <contact@xxxxxxxxxxx> wrote: > > > The KMS docs describe "subconnector" to be defined as "downstream port" for DP. > > Can USB-C (or USB) be seen as a DP downstream port? > > To expand on this a bit: I'm wondering if we're mixing apples and > oranges here. The current values of "subconnector" typically describe > the lower-level protocol tunneled inside DP. For instance, VGA can be > tunneled inside the DP cable when using DP → VGA adapter. Doesn't this contradict the example use case you gave in your previous e-mail, with wlroots stating "DP-3 via DVI-D" ? I understand that as DP carried over a DVI-D physical connector, did I get it wrong ? > However, in the USB-C case, DP itself is tunneled inside USB-C. And you > might use a USB-C → DP adapter. So it's not really *sub*connector, it's > more of a *super*connector, right? > > I think [1] is somewhat related, since it also allows user-space to > discover whether a connector uses USB-C. But relying on sysfs to figure > this out isn't super optimal perhaps. > > [1]: https://lore.kernel.org/dri-devel/20221108185004.2263578-1-wonchung@xxxxxxxxxx/ -- Regards, Laurent Pinchart
