Re: [Intel-gfx] [PATCH v2 2/5] drm/i915: Only populate aux_ch is really needed

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 20 Jun 2023, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Mixing VBT based AUX CH with platform defaults seems like
> a recipe for conflicts. Let's only populate AUX CH if we
> absolutely need it, that is only if we are dealing with
> a DP output or a TC port (which need it due to some power
> well shenanigans).
>
> TODO: double check that real VBTs do in fact populate
>       the AUX CH for HDMI TC legacy ports...
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/g4x_hdmi.c  |  1 -
>  drivers/gpu/drm/i915/display/intel_ddi.c | 12 +++++++++++-
>  2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/g4x_hdmi.c b/drivers/gpu/drm/i915/display/g4x_hdmi.c
> index c1fd13bdc9d2..634b14116d9d 100644
> --- a/drivers/gpu/drm/i915/display/g4x_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/g4x_hdmi.c
> @@ -775,6 +775,5 @@ void g4x_hdmi_init(struct drm_i915_private *dev_priv,
>  
>  	intel_infoframe_init(dig_port);
>  
> -	dig_port->aux_ch = intel_dp_aux_ch(intel_encoder);
>  	intel_hdmi_init_connector(dig_port, intel_connector);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 6cb24a472a9b..662b5ceef3c8 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4676,6 +4676,14 @@ static bool port_strap_detected(struct drm_i915_private *i915, enum port port)
>  	}
>  }
>  
> +static bool need_aux_ch(struct intel_encoder *encoder, bool init_dp)
> +{
> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> +	enum phy phy = intel_port_to_phy(i915, encoder->port);
> +
> +	return init_dp || intel_phy_is_tc(i915, phy);
> +}
> +
>  void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
>  {
>  	struct intel_digital_port *dig_port;
> @@ -4929,7 +4937,9 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
>  
>  	dig_port->dp.output_reg = INVALID_MMIO_REG;
>  	dig_port->max_lanes = intel_ddi_max_lanes(dig_port);
> -	dig_port->aux_ch = intel_dp_aux_ch(encoder);
> +
> +	if (need_aux_ch(encoder, init_dp))
> +		dig_port->aux_ch = intel_dp_aux_ch(encoder);
>  
>  	if (intel_phy_is_tc(dev_priv, phy)) {
>  		bool is_legacy =

-- 
Jani Nikula, Intel Open Source Graphics Center