On Thu, 3 Aug 2023 at 18:31, Simon Ser <contact@xxxxxxxxxxx> 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. My opinion hasn't changed: I think this should be the USB connector with proper DP / DVI / HDMI / etc. subconnector type (or lack of it). In the end, the physical connector on the side of laptop is USB-C. If we want to make it different from GUD, we might want to define a USB-DP connector type (which would also include SlimPort). > > 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/ -- With best wishes Dmitry
