Re: [PATCH 3/4] drm/uapi: document the USB subconnector type

[Simon Ser]

On Thursday, August 3rd, 2023 at 22:44, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:

> 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 ?

No, this is DVI carried over DP. DP cannot be carried over VGA/DVI/HDMI,
but VGA/DVI/HDMI can be carried over DP.