[Intel-gfx] [PATCH 1/3] drm/i915: Dont enable hpd for eDP

[Ville Syrjälä]

On Mon, Aug 10, 2015 at 03:14:36PM +0300, Jani Nikula wrote:
> On Mon, 10 Aug 2015, Sivakumar Thulasimani <sivakumar.thulasimani at intel.com> wrote:
> > On 8/10/2015 5:07 PM, Jani Nikula wrote:
> >> On Mon, 10 Aug 2015, Sivakumar Thulasimani <sivakumar.thulasimani at intel.com> wrote:
> >>> Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
> >>>
> >>> On 8/10/2015 10:35 AM, Sonika Jindal wrote:
> >>>> With HPD support added for all ports including PORT_A, setting hpd_pin will
> >>>> result in enabling of hpd to edp as well. There is no need to enable HPD on
> >>>> PORT_A hence this patch removes hpd_pin update for PORT_A, where edp will
> >>>> be connected. it can be added back when required
> >> What? You can't just go ahead and remove HPD from eDP sinks.
> >>
> >> BR,
> >> Jani.
> > Nope, we are not removing HPD for edp sinks, it was never there in the 
> > first place. It was
> > enabled for CHV (even there by mistake since PORT B/C was both DP and 
> > eDP) but it was
> > never there for any other plaforms nor is it used for any purpose (PSR 
> > must use it, but i
> > dont see code for it as well).
> 
> Are you saying there's no HPD enabled in our *hardware* for eDP? Or
> driver?
> 
> My point is, is this patch making it harder to enable eDP hpd handling
> (e.g. for PSR or DP link re-training) in the future? We currently take
> it into account in a few places, and if we start removing that, it will
> be a loss of effort to first remove and then add it back.

I have a branch with (untested) port A/E HPD support (+ a bunch of SPT+
irq handler reorganization). I guess I should post that in case people
are interested in this stuff.

-- 
Ville Syrjälä
Intel OTC