Re: [PATCH v3 5/7] drm/nouveau: utilize subconnector property for DP

From: "Ville Syrjälä" <ville.syrjala-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: Ilia Mirkin <imirkin-FrUbXkNCsVf2fBVCVOL8/A@public.gmane.org>
Cc: nouveau
	<nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
	Oleg Vasilev
	<oleg.vasilev-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Ben Skeggs <bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	dri-devel
	<dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
	Emil Velikov
	<emil.velikov-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org>
Subject: Re: [PATCH v3 5/7] drm/nouveau: utilize subconnector property for DP
Date: Wed, 28 Aug 2019 18:41:37 +0300	[thread overview]
Message-ID: <20190828154137.GG7482@intel.com> (raw)
In-Reply-To: <CAKb7UviDZZkOAQWu+_Lqw3TbhnKq138XM5HXNRUzoc5GCCZGNA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On Wed, Aug 28, 2019 at 11:11:41AM -0400, Ilia Mirkin wrote:
> On Wed, Aug 28, 2019 at 10:54 AM Ville Syrjälä
> <ville.syrjala@linux.intel.com> wrote:
> >
> > On Wed, Aug 28, 2019 at 10:47:08AM -0400, Ilia Mirkin wrote:
> > > On Wed, Aug 28, 2019 at 10:38 AM Ville Syrjälä
> > > <ville.syrjala@linux.intel.com> wrote:
> > > >
> > > > On Mon, Aug 26, 2019 at 09:36:50AM -0400, Ilia Mirkin wrote:
> > > > > This should probably be fixed to account for the scenario where an
> > > > > HDMI connector is plugged directly into the DP++ port. I don't think
> > > > > the dp.subconnector property will be valid in that case.
> > > > > (Unfortunately I don't remember how one detects that particular
> > > > > situation.)
> > > >
> > > > One may or may not be able to detect it very well. I've seen dongles
> > > > that automagically change the DFP type from DP++ to DP/HDMI depending
> > > > on what's plugged in, and I've also seen dongles that leave the DFP
> > > > type to DP++.
> > >
> > > Well, our internal logic certainly knows if it's driving DP or TMDS. I
> > > just don't remember how it knows this.
> >
> > You'll be driving DP in this case. The DFP will be the one driving
> > DP or TMDS depending on what's plugged in.
> 
> OK. That's not the case I was worried about though :)
> 
> I'm worried about the case where you plug a true HDMI thing into the
> DP port, which will then be driven by HDMI and none of the dp.* things
> will be set (I don't remember, but they might even be in a union). I
> think Intel multiplies connectors for this, but nouveau/amd just have
> a single connector that handles both.

Ah. Yeah, that's a bit more confusing since you kinda now have two
levels of subconnectors. Not sure how to deal with that tbh.

-- 
Ville Syrjälä
Intel
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