[Intel-gfx] [v3] drm/i915/display: Extend DP HDR support to hsw+

[Shankar, Uma]

> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Sent: Thursday, March 24, 2022 6:30 PM
> To: Shankar, Uma <uma.shankar at intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [v3] drm/i915/display: Extend DP HDR support to hsw+
> 
> On Thu, Mar 24, 2022 at 11:58:15AM +0000, Shankar, Uma wrote:
> >
> >
> > > -----Original Message-----
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Sent: Thursday, March 24, 2022 5:12 PM
> > > To: Shankar, Uma <uma.shankar at intel.com>
> > > Cc: intel-gfx at lists.freedesktop.org
> > > Subject: Re: [v3] drm/i915/display: Extend DP HDR support to hsw+
> > >
> > > On Thu, Mar 24, 2022 at 04:39:59PM +0530, Uma Shankar wrote:
> > > > HSW+ platforms are able to send out HDR Metadata SDP DIP
> > > > packet as GMP. Hence, extending the support for HDR on DP encoders
> > > > for the same.
> > > >
> > > > v2: Limited to non eDP ports on hsw/bdw and removed it for lspcon
> > > > as it is done separately (suggested by Ville)
> > > >
> > > > v3: Added helper and limited eDP restriction to port A (Ville)
> > > >
> > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5389
> > > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > > Signed-off-by: Uma Shankar <uma.shankar at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_dp.c | 22
> > > > +++++++++++++++++++++-
> > > >  1 file changed, 21 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > index 9e19165fd175..c993d82c7ec9 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > @@ -4913,6 +4913,26 @@ bool intel_dp_is_port_edp(struct
> > > > drm_i915_private
> > > *dev_priv, enum port port)
> > > >  	return intel_bios_is_port_edp(dev_priv, port);  }
> > > >
> > > > +static bool
> > > > +has_gamut_metadata_dip(struct drm_i915_private *dev_priv,
> > >
> > > s/dev_priv/i915/ for modern style
> >
> > Ok, will update
> >
> > >
> > > > +		       struct intel_dp *intel_dp, enum port port) {
> > > > +	if (intel_bios_is_lspcon_present(dev_priv, port))
> > > > +		return false;
> > > > +
> > > > +	if (DISPLAY_VER(dev_priv) >= 10 && !IS_GEMINILAKE(dev_priv))
> > > > +		return true;
> > >
> > > DISPLAY_VER >= 11
> > >
> > > > +
> > > > +	if (port == PORT_A && intel_dp_is_edp(intel_dp))
> > >
> > > The is_edp check is still wrong. Should be just port==A.
> > > Also allows you to drop the intel_dp argument to the function.
> >
> > In the register description for VIDEO_DIP_CTL, (Bspec:7748)
> > BitField: VDIP Enable GMP
> > [BDW, SKL, BXT, KBL, KBLH, GLK, GLV, CFL, WHL, AML, CML, CNL, LKFR]
> > GMP is not supported on transcoder EDP going to DDI A.
> >
> > That's why was checking for eDP. But port A check should be good enough.
> 
> Transcoder EDP is hardwired to DDI A. Despite the name it has nothing to do with
> eDP vs. DP.
> 
> Having the eDP check would be just wrong because it would then attach the property
> to DDI A when it is used as an external DP port. And yes, such machines do in fact
> exist.

Yeah got the point. Thanks Ville for the review and valuable comments.

Regards,
Uma Shankar
> 
> > Will drop it.
> >
> > > > +		return false;
> > > > +
> > > > +	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv) ||
> > > > +	    IS_GEMINILAKE(dev_priv) || DISPLAY_VER(dev_priv) >= 9)
> > > > +		return true;
> > >
> > > The IS_GLK check is redundant.
> >
> > Yeah will drop it.
> >
> > > > +
> > > > +	return false;
> > > > +}
> > > > +
> > > >  static void
> > > >  intel_dp_add_properties(struct intel_dp *intel_dp, struct
> > > > drm_connector *connector)  { @@ -4939,7 +4959,7 @@
> > > > intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector
> *connect
> > > >  		intel_attach_dp_colorspace_property(connector);
> > > >  	}
> > > >
> > > > -	if (IS_GEMINILAKE(dev_priv) || DISPLAY_VER(dev_priv) >= 11)
> > > > +	if (has_gamut_metadata_dip(dev_priv, intel_dp, port))
> > > >  		drm_object_attach_property(&connector->base,
> > > >  					   connector->dev-
> > > >mode_config.hdr_output_metadata_property,
> > > >  					   0);
> > > > --
> > > > 2.25.1
> > >
> > > --
> > > Ville Syrjälä
> > > Intel
> 
> --
> Ville Syrjälä
> Intel