[Intel-gfx] [PATCH v1] drm/i915: Call intel_edp_init_connector only for eDP.

[Lisovskiy, Stanislav]

On Tue, 2020-02-11 at 15:03 +0200, Jani Nikula wrote:
> On Tue, 11 Feb 2020, Stanislav Lisovskiy <
> stanislav.lisovskiy at intel.com> wrote:
> > I guess it would still be nice to make the code less confusing
> > and do not call eDP specific function, for non-eDP connectors
> > just to immediately return true(success) value as a hack.
> > 
> > So simply extracted that check out from this function,
> > that we simply don't call it for non-eDP connectors. Bingo.
> 
> Fair enough, I guess...
> 
> Though I could be persuaded to take a patch for the reverse, because
> generally we prefer localized knowledge in the callee than in a
> potentially irrelevant place in the caller.
> 
> Consider the intel_dp_mst_encoder_init() call in the context of this
> patch. We call it, and the function itself decides whether MST init
> is
> relevant or not. But I presume you wouldn't suggest pulling in all
> the
> conditions from there one level higher?
> 
> Would your opinion on intel_edp_init_connector() be different if the
> conditions were more than just the single intel_dp_is_edp()? Or if we
> moved all of eDP support to a separate file?

Well, to me at least intel_edp_init_connector means that we are going
to init an eDP connector, which already assumes that, we already should
know that this is an eDP connector :) 
Otherwise it should have somewhat different name, not saying that this
is the best philosophy, but generally I would prefer the functions to
be solely responsible for a single thing so that that init function is
supposed to do only init, but not also some detection/checking or any 
other side effects.

So that there is a clear visibility what we are doing, if it's an init
then we really do only init or if we supposed to detect something
first, let it be a separate thing..

Also this uses a return value in confusing way, i.e returning "Success"
status for non-eDP from intel_edp_init_connector seems kind of
confusing.

Stan

> 
> BR,
> Jani.
> 
> 
> > 
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp.c | 13 ++++++-------
> >  1 file changed, 6 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index f4dede6253f8..9bd36197a43d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -7370,9 +7370,6 @@ static bool intel_edp_init_connector(struct
> > intel_dp *intel_dp,
> >  	intel_wakeref_t wakeref;
> >  	struct edid *edid;
> >  
> > -	if (!intel_dp_is_edp(intel_dp))
> > -		return true;
> > -
> >  	INIT_DELAYED_WORK(&intel_dp->panel_vdd_work,
> > edp_panel_vdd_work);
> >  
> >  	/*
> > @@ -7590,10 +7587,12 @@ intel_dp_init_connector(struct
> > intel_digital_port *intel_dig_port,
> >  	intel_dp_mst_encoder_init(intel_dig_port,
> >  				  intel_connector->base.base.id);
> >  
> > -	if (!intel_edp_init_connector(intel_dp, intel_connector)) {
> > -		intel_dp_aux_fini(intel_dp);
> > -		intel_dp_mst_encoder_cleanup(intel_dig_port);
> > -		goto fail;
> > +	if (intel_dp_is_edp(intel_dp)) {
> > +		if (!intel_edp_init_connector(intel_dp,
> > intel_connector)) {
> > +			intel_dp_aux_fini(intel_dp);
> > +			intel_dp_mst_encoder_cleanup(intel_dig_port);
> > +			goto fail;
> > +		}
> >  	}
> >  
> >  	intel_dp_add_properties(intel_dp, connector);
> 
>