Re: [PATCH 2/2] drm/i915: take a power domain reference while checking the HDMI live status

Imre Deak
2015-11-19T19:13:29Z

On Thu, 2015-11-19 at 21:08 +0200, Ville Syrjälä wrote:
> On Thu, Nov 19, 2015 at 08:55:01PM +0200, Imre Deak wrote:
> > There are platforms that don't need the full GMBUS power domain
> > (PCH, BXT) while others do (VLV/CHV). For optimizing this we
> > would need to add a new power domain, but it's not clear how much
> > we
> > would benefit given the short time we hold the reference. So for
> > now
> > let's keep things simple.
>
> Actually on PCH platforms the gmbus domain means just just an
> rpm ref since the gmbus hw lives in the PCH.

Ah right.

> And IIRC on BXT gmbus lives in pw0 so same deal really.

It's in PW2 there. I'll fix the commit message.

> And for vlv/chv we should just need the disp2d well, which
> is exactly what we get with the gmbus domain.
>
> So I don't think there's actually anything to optimize here
> with current platforms.
>
> Both patches look fine to me:
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> >
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_hdmi.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c
> > b/drivers/gpu/drm/i915/intel_hdmi.c
> > index 17ced03..bdd462e 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -1393,6 +1393,8 @@ intel_hdmi_detect(struct drm_connector
> > *connector, bool force)
> >   DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
> >         connector->base.id, connector->name);
> >
> > + intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
> > +
> >   while (!live_status && --retry) {
> >   live_status =
> > intel_digital_port_connected(dev_priv,
> >   hdmi_to_dig_port(intel_hdmi));
> > @@ -1412,6 +1414,8 @@ intel_hdmi_detect(struct drm_connector
> > *connector, bool force)
> >   } else
> >   status = connector_status_disconnected;
> >
> > + intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
> > +
> >   return status;
> >  }
> >
> > --
> > 2.5.0
> >
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