[PATCH 0/5] Initial DisplayPort OUI probing

[Alex Deucher]

On Mon, May 21, 2012 at 4:11 PM, Adam Jackson <ajax at redhat.com> wrote:
> On Mon, 2012-05-21 at 15:27 -0400, Alex Deucher wrote:
>
>> I'm pretty sure it's needed for looking up the display topology for
>> things like DP 1.2 MST.  We probably need to decide on some changes to
>> the DRM KMS topology to deal with multiple displays being driven from
>> a single connector (sub-connectors maybe?).  A single port could
>> potentially drive a HDMI monitor or a DVI monitor or one or more DP
>> monitors.
>>
>> Acked-by: Alex Deucher <alexander.deucher at amd.com>
>
> I had been considering MST to be multiple CRTCs and some quasi-virtual
> connectors.  Does that not match the hardware?

That's the basic idea.  At the hw level you have multiple crtcs and
digital encoders feeding a single digital phy which is wired to a
connector on the board.  The phy takes care of muxing the source
streams.  MST works by enclosing multiple video streams (plus optional
secondary streams like audio) into VC (virtual channel) packets.  The
VC packets are scheduled into timeslots in the main link timing.
Setup is via aux.  The DP bus starts to look more like a network.
Additionally, you can tunnel other things like USB.  Should be "fun."

Alex

>
> - ajax