Re: [PATCH 4/4] drm/bridge: ti-sn65dsi86: Add NO_CONNECTOR support

[Rob Clark]

On Thu, Aug 12, 2021 at 1:08 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> Laurent,
>
> On Thu, Aug 12, 2021 at 12:26 PM Laurent Pinchart
> <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> >
> > Hi Rob,
> >
> > Thank you for the patch.
> >
> > On Wed, Aug 11, 2021 at 04:52:50PM -0700, Rob Clark wrote:
> > > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> > >
> > > Slightly awkward to fish out the display_info when we aren't creating
> > > own connector.  But I don't see an obvious better way.
> >
> > We need a bit more than this, to support the NO_CONNECTOR case, the
> > bridge has to implement a few extra operations, and set the bridge .ops
> > field. I've submitted two patches to do so a while ago:
> >
> > - [RFC PATCH 08/11] drm/bridge: ti-sn65dsi86: Implement bridge connector operations ([1])
>
> Rob asked me about this over IRC, so if he left it out and it's needed
> then it's my fault. However, I don't believe it's needed until your
> series making this bridge chip support full DP. For the the eDP case
> the bridge chip driver in ToT no longer queries the EDID itself. It
> simply provides an AUX bus to the panel driver and the panel driver
> queries the EDID. I think that means we don't need to add
> DRM_BRIDGE_OP_EDID, right?
>
> I was also wondering if in the full DP case we should actually model
> the physical DP jack as a drm_bridge and have it work the same way. It
> would get probed via the DP AUX bus just like a panel. I seem to
> remember Stephen Boyd was talking about modeling the DP connector as a
> drm_bridge because it would allow us to handle the fact that some TCPC
> chips could only support HBR2 whereas others could support HBR3. Maybe
> it would end up being a fairly elegant solution?
>
> > - [RFC PATCH 09/11] drm/bridge: ti-sn65dsi86: Make connector creation optional ([2])
> >
> > The second patch is similar to the first half of this patch, but misses
> > the cleanup code. I'll try to rebase this and resubmit, but it may take
> > a bit of time.
>
> Whoops! You're right that Rob's patch won't work at all because we'll
> just hit the "Fix bridge driver to make connector optional!" case. I
> should have noticed that. :(

Yes, indeed.. once I fix that, I get no display..

Not sure if Laurent is still working on his series, otherwise I can
try to figure out what bridge ops are missing

BR,
-R