Re: [Intel-gfx] [PATCH 2/2] drm/i915/pps: Enable 2nd pps for dual EDP scenario

["Manna, Animesh" <animesh.manna@intel.com>]

> -----Original Message-----
> From: Nikula, Jani <jani.nikula@intel.com>
> Sent: Tuesday, October 4, 2022 1:19 PM
> To: Manna, Animesh <animesh.manna@intel.com>; intel-
> gfx@lists.freedesktop.org
> Cc: Manna, Animesh <animesh.manna@intel.com>; Ville Syrjälä
> <ville.syrjala@linux.intel.com>; Shankar, Uma <uma.shankar@intel.com>
> Subject: Re: [PATCH 2/2] drm/i915/pps: Enable 2nd pps for dual EDP scenario
> 
> On Tue, 27 Sep 2022, Animesh Manna <animesh.manna@intel.com> wrote:
> > From display gen12 onwards to support dual EDP two instances of pps added.
> > Currently backlight controller and pps instance can be mapped together
> > for a specific panel. Extended support for gen12 for dual EDP usage.
> 
> Frankly the dual PPS support was there already, but broken. This fixes it, and
> enables it for display 12+.
> 
> >
> > v1: Iniital revision.
> > v2: Called intel_bios_panel_init w/o PNPID before intel_pps_init.
> > [Jani]
> > v3: Set pps_id to -1 for pnpid type of panel which will be used by
> > bxt_power_sequencer_idx() to set 2nd pps instance as default for 2nd
> > EDP panel. [Jani]
> >
> > Cc: Jani Nikula <jani.nikula@intel.com>
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Uma Shankar <uma.shankar@intel.com>
> > Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bios.c          | 13 +++++++++++--
> >  drivers/gpu/drm/i915/display/intel_bios.h          |  2 +-
> >  drivers/gpu/drm/i915/display/intel_display_types.h |  1 +
> >  drivers/gpu/drm/i915/display/intel_dp.c            | 10 +++++++---
> >  drivers/gpu/drm/i915/display/intel_pps.c           | 12 +++++++++++-
> >  5 files changed, 31 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
> > b/drivers/gpu/drm/i915/display/intel_bios.c
> > index 28bdb936cd1f..2015b6592754 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -3175,13 +3175,14 @@ void intel_bios_init(struct drm_i915_private
> *i915)
> >  	kfree(oprom_vbt);
> >  }
> >
> > -void intel_bios_init_panel(struct drm_i915_private *i915,
> > +bool intel_bios_init_panel(struct drm_i915_private *i915,
> >  			   struct intel_panel *panel,
> >  			   const struct intel_bios_encoder_data *devdata,
> >  			   const struct edid *edid)
> >  {
> > -	init_vbt_panel_defaults(panel);
> > +	bool retry = false;
> >
> > +	init_vbt_panel_defaults(panel);
> >  	panel->vbt.panel_type = get_panel_type(i915, devdata, edid);
> >
> >  	parse_panel_options(i915, panel);
> > @@ -3195,6 +3196,14 @@ void intel_bios_init_panel(struct drm_i915_private
> *i915,
> >  	parse_psr(i915, panel);
> >  	parse_mipi_config(i915, panel);
> >  	parse_mipi_sequence(i915, panel);
> > +
> > +	if (panel->vbt.panel_type == PANEL_TYPE_PNPID ||
> > +	    panel->vbt.panel_type == PANEL_TYPE_FALLBACK) {
> > +		panel->vbt.edp.pps_id = -1;
> > +		retry = true;
> > +	}
> 
> Why do you initialize everything above if you know the panel type is garbage and
> we need to retry? I don't think the above functions were designed with the idea
> they could be called multiple times for the same panel.
> 
> Return early if you know it's wrong. Also, don't return true if the EDID is
> provided.

Thanks Jani for review, have sent the v4 after addressing the above comments.

Regards,
Animesh

> 
> BR,
> Jani.
> 
> > +
> > +	return retry;
> >  }
> >
> >  /**
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.h
> > b/drivers/gpu/drm/i915/display/intel_bios.h
> > index e375405a7828..f8ef0274f3ee 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.h
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.h
> > @@ -232,7 +232,7 @@ struct mipi_pps_data {  } __packed;
> >
> >  void intel_bios_init(struct drm_i915_private *dev_priv); -void
> > intel_bios_init_panel(struct drm_i915_private *dev_priv,
> > +bool intel_bios_init_panel(struct drm_i915_private *dev_priv,
> >  			   struct intel_panel *panel,
> >  			   const struct intel_bios_encoder_data *devdata,
> >  			   const struct edid *edid);
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index b78b29951241..0edc0b8f3743 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -307,6 +307,7 @@ struct intel_vbt_panel_data {
> >  		int preemphasis;
> >  		int vswing;
> >  		int bpp;
> > +		int pps_id;
> >  		struct edp_power_seq pps;
> >  		u8 drrs_msa_timing_delay;
> >  		bool low_vswing;
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index c19e99ee06b6..a94fc947cdb3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -5203,6 +5203,7 @@ static bool intel_edp_init_connector(struct intel_dp
> *intel_dp,
> >  	bool has_dpcd;
> >  	enum pipe pipe = INVALID_PIPE;
> >  	struct edid *edid;
> > +	bool retry;
> >
> >  	if (!intel_dp_is_edp(intel_dp))
> >  		return true;
> > @@ -5222,6 +5223,9 @@ static bool intel_edp_init_connector(struct intel_dp
> *intel_dp,
> >  		return false;
> >  	}
> >
> > +	retry = intel_bios_init_panel(dev_priv, &intel_connector->panel,
> > +				      encoder->devdata, NULL);
> > +
> >  	intel_pps_init(intel_dp);
> >
> >  	/* Cache DPCD and EDID for edp. */
> > @@ -5255,9 +5259,9 @@ static bool intel_edp_init_connector(struct intel_dp
> *intel_dp,
> >  		edid = ERR_PTR(-ENOENT);
> >  	}
> >  	intel_connector->edid = edid;
> > -
> > -	intel_bios_init_panel(dev_priv, &intel_connector->panel,
> > -			      encoder->devdata, IS_ERR(edid) ? NULL : edid);
> > +	if (retry)
> > +		intel_bios_init_panel(dev_priv, &intel_connector->panel,
> > +				      encoder->devdata, IS_ERR(edid) ? NULL :
> edid);
> >
> >  	intel_panel_add_edid_fixed_modes(intel_connector,
> >  					 intel_connector->panel.vbt.drrs_type
> != DRRS_TYPE_NONE, diff
> > --git a/drivers/gpu/drm/i915/display/intel_pps.c
> > b/drivers/gpu/drm/i915/display/intel_pps.c
> > index b972fa6ec00d..da98b180639a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_pps.c
> > +++ b/drivers/gpu/drm/i915/display/intel_pps.c
> > @@ -218,6 +218,16 @@ bxt_power_sequencer_idx(struct intel_dp *intel_dp)
> >  	/* We should never land here with regular DP ports */
> >  	drm_WARN_ON(&dev_priv->drm, !intel_dp_is_edp(intel_dp));
> >
> > +	if (connector->panel.vbt.edp.pps_id == -1) {
> > +		/*
> > +		 * Use 2nd PPS instance as default for 2nd EDP panel.
> > +		 */
> > +		if (connector->encoder->port == PORT_A)
> > +			return 0;
> > +		else
> > +			return 1;
> > +	}
> > +
> >  	if (!intel_dp->pps.pps_reset)
> >  		return backlight_controller;
> >
> > @@ -1430,7 +1440,7 @@ void intel_pps_init(struct intel_dp *intel_dp)
> >  	intel_dp->pps.initializing = true;
> >  	INIT_DELAYED_WORK(&intel_dp->pps.panel_vdd_work,
> > edp_panel_vdd_work);
> >
> > -	if (IS_GEMINILAKE(i915) || IS_BROXTON(i915))
> > +	if (IS_GEMINILAKE(i915) || IS_BROXTON(i915) || DISPLAY_VER(i915) >=
> > +12)
> >  		intel_dp->get_pps_idx = bxt_power_sequencer_idx;
> >  	else if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
> >  		intel_dp->get_pps_idx = vlv_power_sequencer_pipe;
> 
> --
> Jani Nikula, Intel Open Source Graphics Center