[Intel-gfx] [PATCH 1/4] drm/i915: Respect alternate_aux_channel for all DDI ports

[Jim Bride]

On Tue, Oct 11, 2016 at 08:52:45PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> The VBT provides the platform a way to mix and match the DDI ports vs.
> AUX channels. Currently we only trust the VBT for DDI E, which has no
> corresponding AUX channel of its own. However it is possible that some
> board might use some non-standard DDI vs. AUX port routing even for
> the other ports. Perhaps for signal routing reasons or something,
> So let's generalize this and trust the VBT for all ports.
> 
> For now we'll limit this to DDI platforms, as we trust the VBT a bit
> more there anyway when it comes to the DDI ports. I've structured
> the code in a way that would allow us to easily expand this to
> other platforms as well, by simply filling in the ddi_port_info.
> 
> v2: Drop whitespace changes, keep MISSING_CASE() for unknown
>     aux ch assignment, include a commit message, include debug
>     message during init
> 
> Cc: stable at vger.kernel.org
> Cc: Maarten Maathuis <madman2003 at gmail.com>
> Tested-by: Maarten Maathuis <madman2003 at gmail.com>
> References: https://bugs.freedesktop.org/show_bug.cgi?id=97877
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: Jim Bride <jim.bride at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_dp.c | 71 +++++++++++++++++++++++------------------
>  1 file changed, 40 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 5992093e1814..b0753b272101 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1108,6 +1108,44 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
>  	return ret;
>  }
>  
> +static enum port intel_aux_port(struct drm_i915_private *dev_priv,
> +				enum port port)
> +{
> +	const struct ddi_vbt_port_info *info =
> +		&dev_priv->vbt.ddi_port_info[port];
> +	enum port aux_port;
> +
> +	if (!info->alternate_aux_channel) {
> +		DRM_DEBUG_KMS("using AUX %c for port %c (platform default)\n",
> +			      port_name(port), port_name(port));
> +		return port;
> +	}
> +
> +	switch (info->alternate_aux_channel) {
> +	case DP_AUX_A:
> +		aux_port = PORT_A;
> +		break;
> +	case DP_AUX_B:
> +		aux_port = PORT_B;
> +		break;
> +	case DP_AUX_C:
> +		aux_port = PORT_C;
> +		break;
> +	case DP_AUX_D:
> +		aux_port = PORT_D;
> +		break;
> +	default:
> +		MISSING_CASE(info->alternate_aux_channel);
> +		aux_port = PORT_A;
> +		break;
> +	}
> +
> +	DRM_DEBUG_KMS("using AUX %c for port %c (VBT)\n",
> +		      port_name(aux_port), port_name(port));
> +
> +	return aux_port;
> +}
> +
>  static i915_reg_t g4x_aux_ctl_reg(struct drm_i915_private *dev_priv,
>  				       enum port port)
>  {
> @@ -1168,36 +1206,9 @@ static i915_reg_t ilk_aux_data_reg(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> -/*
> - * On SKL we don't have Aux for port E so we rely
> - * on VBT to set a proper alternate aux channel.
> - */
> -static enum port skl_porte_aux_port(struct drm_i915_private *dev_priv)
> -{
> -	const struct ddi_vbt_port_info *info =
> -		&dev_priv->vbt.ddi_port_info[PORT_E];
> -
> -	switch (info->alternate_aux_channel) {
> -	case DP_AUX_A:
> -		return PORT_A;
> -	case DP_AUX_B:
> -		return PORT_B;
> -	case DP_AUX_C:
> -		return PORT_C;
> -	case DP_AUX_D:
> -		return PORT_D;
> -	default:
> -		MISSING_CASE(info->alternate_aux_channel);
> -		return PORT_A;
> -	}
> -}
> -
>  static i915_reg_t skl_aux_ctl_reg(struct drm_i915_private *dev_priv,
>  				       enum port port)
>  {
> -	if (port == PORT_E)
> -		port = skl_porte_aux_port(dev_priv);
> -
>  	switch (port) {
>  	case PORT_A:
>  	case PORT_B:
> @@ -1213,9 +1224,6 @@ static i915_reg_t skl_aux_ctl_reg(struct drm_i915_private *dev_priv,
>  static i915_reg_t skl_aux_data_reg(struct drm_i915_private *dev_priv,
>  					enum port port, int index)
>  {
> -	if (port == PORT_E)
> -		port = skl_porte_aux_port(dev_priv);
> -
>  	switch (port) {
>  	case PORT_A:
>  	case PORT_B:
> @@ -1253,7 +1261,8 @@ static i915_reg_t intel_aux_data_reg(struct drm_i915_private *dev_priv,
>  static void intel_aux_reg_init(struct intel_dp *intel_dp)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> -	enum port port = dp_to_dig_port(intel_dp)->port;
> +	enum port port = intel_aux_port(dev_priv,
> +					dp_to_dig_port(intel_dp)->port);
>  	int i;
>  
>  	intel_dp->aux_ch_ctl_reg = intel_aux_ctl_reg(dev_priv, port);
> -- 
> 2.7.4
> 
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