Re: [PATCH 3/3] drm/i915: Introduce intel_ddi_dp_voltage_max()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Feb 23, 2017 at 07:44:48PM +0200, David Weinehall wrote:
> On Thu, Feb 23, 2017 at 07:35:07PM +0200, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Rather than sprinkling ideas of how big the DDI buf translation tables
> > are somewhere in intel_dp.c, let's concentrate it all in intel_ddi.c
> > where the actual tables are defined. To that end we introduce
> > intel_ddi_dp_voltage_max() which will actually look at the proper
> > translation table to determine what is the maximum voltage swing level
> > supported.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
> 
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c | 18 ++++++++++++++++++
> >  drivers/gpu/drm/i915/intel_dp.c  |  5 ++---
> >  drivers/gpu/drm/i915/intel_drv.h |  2 ++
> >  3 files changed, 22 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index 6f8e57f127e5..0c3665f9e4f4 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -1615,6 +1615,24 @@ static void bxt_ddi_vswing_sequence(struct drm_i915_private *dev_priv,
> >  				     ddi_translations[level].deemphasis);
> >  }
> >  
> > +u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > +	int n_entries;
> > +
> > +	if (encoder->type == INTEL_OUTPUT_EDP)
> > +		intel_ddi_get_buf_trans_edp(dev_priv, &n_entries);
> > +	else
> > +		intel_ddi_get_buf_trans_dp(dev_priv, &n_entries);
> > +
> > +	if (WARN_ON(n_entries < 1))
> > +		n_entries = 1;
> > +	if (WARN_ON(n_entries > ARRAY_SIZE(index_to_dp_signal_levels)))
> > +		n_entries = ARRAY_SIZE(index_to_dp_signal_levels);
> > +
> > +	return index_to_dp_signal_levels[n_entries - 1];

I just realized myself that this needs to mask out the preemphasis bits.
I'll fire off a v2.

> > +}
> > +
> >  static uint32_t translate_signal_level(int signal_levels)
> >  {
> >  	int i;
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 024798a9c016..e72c92a08c81 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -3098,9 +3098,8 @@ intel_dp_voltage_max(struct intel_dp *intel_dp)
> >  	if (IS_GEN9_LP(dev_priv))
> >  		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
> >  	else if (INTEL_GEN(dev_priv) >= 9) {
> > -		if (dev_priv->vbt.edp.low_vswing && port == PORT_A)
> > -			return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
> > -		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
> > +		struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> > +		return intel_ddi_dp_voltage_max(encoder);
> >  	} else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> >  		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
> >  	else if (IS_GEN7(dev_priv) && port == PORT_A)
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 3c8aaca947d3..e9a90dcd15df 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1233,6 +1233,8 @@ void intel_ddi_clock_get(struct intel_encoder *encoder,
> >  			 struct intel_crtc_state *pipe_config);
> >  void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state);
> >  uint32_t ddi_signal_levels(struct intel_dp *intel_dp);
> > +u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder);
> > +
> >  unsigned int intel_fb_align_height(struct drm_i915_private *dev_priv,
> >  				   unsigned int height,
> >  				   uint32_t pixel_format,
> > -- 
> > 2.10.2
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC
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