[PATCH 0/5] Initial DisplayPort OUI probing

Alex Deucher alexdeucher at gmail.com
Mon May 21 12:27:35 PDT 2012


On Mon, May 21, 2012 at 2:47 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Mon, May 21, 2012 at 01:41:47PM -0400, Adam Jackson wrote:
>> On Mon, 2012-05-14 at 16:05 -0400, Adam Jackson wrote:
>> > DisplayPort has an escape hatch by which devices can identify each other.
>> > I'm not super thrilled that it does, since that's just a clever way of
>> > getting the spec to explicitly bless interoperability bugs.  But it may
>> > be useful information when debugging link training problems, and there's
>> > a cute trick you can do on iMacs that I think will require knowing this
>> > information, so we may as well fill it in.
>> >
>> > Tested on a Lenovo T500 against a DP->VGA adaptor (which turns out to be
>> > an ST Microelectronics chip, who knew) and an HP LP2480zx (which does
>> > not advertise OUI support, but also harmlessly returns 0s for the OUI
>> > registers if you read them anyway).
>>
>> Bump.  Any takers?
>
> I have no clue about this (still trying to get hold of the dp spec), but I
> fear we need this. So
>

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>

> Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> --
> Daniel Vetter
> Mail: daniel at ffwll.ch
> Mobile: +41 (0)79 365 57 48
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