Re: [PATCH v2 3/5] drm/msm/dp: Support up to 3 DP controllers

[Doug Anderson <dianders@chromium.org>]

Hi,

On Thu, Aug 26, 2021 at 10:20 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Bjorn Andersson (2021-08-25 16:42:31)
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 2c7de43f655a..4a6132c18e57 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -78,6 +78,8 @@ struct dp_display_private {
> >         char *name;
> >         int irq;
> >
> > +       int id;
> > +
> >         /* state variables */
> >         bool core_initialized;
> >         bool hpd_irq_on;
> > @@ -115,8 +117,19 @@ struct dp_display_private {
> >         struct dp_audio *audio;
> >  };
> >
> > +
> > +struct msm_dp_config {
> > +       phys_addr_t io_start[3];
>
> Can this be made into another struct, like msm_dp_desc, that also
> indicates what type of DP connector it is, i.e. eDP vs DP? That would
> help me understand in modetest and /sys/class/drm what sort of connector
> is probing. dp_drm_connector_init() would need to pass the type of
> connector appropriately. Right now, eDP connectors still show up as DP
> instead of eDP in sysfs.

I'm not convinced that's the right way to do it. I think the right way
forward here is to look at whether drm_of_find_panel_or_bridge() finds
a panel. If it finds a panel then we're eDP. If it doesn't then we're
DP. That matches roughly what Laurent was planning to do for
ti-sn65dsi86:

https://lore.kernel.org/all/20210322030128.2283-11-laurent.pinchart+renesas@ideasonboard.com/

I know technically an eDP and DP controller can have different sets of
features but I think what we really are trying to communicate to
modetest is whether an internal panel or external display is
connected, right?


-Doug