Re: [Intel-gfx] [PATCH 15/17] drm/i915/dg2: use 128b/132b transcoder DDI mode

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

On Wed, Aug 18, 2021 at 09:10:50PM +0300, Jani Nikula wrote:
> 128b/132b has a separate transcoder DDI mode, which also requires the
> MST transport select to be set. Note that we'll use DP MST also for
> single-stream 128b/132b.
> 
> Having the FDI and 128b/132b modes share the register mode value
> complicates things a bit.
> 
> Bspec: 50493
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 27 ++++++++++++++++++------
>  1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 8b8f5d679b72..1ee817348bf5 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -505,7 +505,10 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
>  		temp |= TRANS_DDI_MODE_SELECT_FDI_OR_128B132B;
>  		temp |= (crtc_state->fdi_lanes - 1) << 1;
>  	} else if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)) {
> -		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
> +		if (crtc_state->port_clock > 1000000)
> +			temp |= TRANS_DDI_MODE_SELECT_FDI_OR_128B132B;
> +		else
> +			temp |= TRANS_DDI_MODE_SELECT_DP_MST;
>  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
>  
>  		if (DISPLAY_VER(dev_priv) >= 12) {
> @@ -693,7 +696,12 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
>  		break;
>  
>  	case TRANS_DDI_MODE_SELECT_FDI_OR_128B132B:
> -		ret = type == DRM_MODE_CONNECTOR_VGA;
> +		if (IS_DG2(dev_priv))
> +			/* 128b/132b */
> +			ret = false;

Maybe introduce HAS_FDI() or something to avoid these platform checks
all over?

> +		else
> +			/* FDI */
> +			ret = type == DRM_MODE_CONNECTOR_VGA;
>  		break;
>  
>  	default:
> @@ -780,8 +788,9 @@ static void intel_ddi_get_encoder_pipes(struct intel_encoder *encoder,
>  		if ((tmp & port_mask) != ddi_select)
>  			continue;
>  
> -		if ((tmp & TRANS_DDI_MODE_SELECT_MASK) ==
> -		    TRANS_DDI_MODE_SELECT_DP_MST)
> +		if ((tmp & TRANS_DDI_MODE_SELECT_MASK) == TRANS_DDI_MODE_SELECT_DP_MST ||
> +		    (IS_DG2(dev_priv) &&
> +		     (tmp & TRANS_DDI_MODE_SELECT_MASK) == TRANS_DDI_MODE_SELECT_FDI_OR_128B132B))
>  			mst_pipe_mask |= BIT(p);
>  
>  		*pipe_mask |= BIT(p);
> @@ -3572,9 +3581,6 @@ static void intel_ddi_read_func_ctl(struct intel_encoder *encoder,
>  		pipe_config->output_types |= BIT(INTEL_OUTPUT_HDMI);
>  		pipe_config->lane_count = 4;
>  		break;
> -	case TRANS_DDI_MODE_SELECT_FDI_OR_128B132B:
> -		pipe_config->output_types |= BIT(INTEL_OUTPUT_ANALOG);
> -		break;
>  	case TRANS_DDI_MODE_SELECT_DP_SST:
>  		if (encoder->type == INTEL_OUTPUT_EDP)
>  			pipe_config->output_types |= BIT(INTEL_OUTPUT_EDP);
> @@ -3603,6 +3609,13 @@ static void intel_ddi_read_func_ctl(struct intel_encoder *encoder,
>  			pipe_config->infoframes.enable |=
>  				intel_hdmi_infoframes_enabled(encoder, pipe_config);
>  		break;
> +	case TRANS_DDI_MODE_SELECT_FDI_OR_128B132B:
> +		if (!IS_DG2(dev_priv)) {
> +			/* FDI */
> +			pipe_config->output_types |= BIT(INTEL_OUTPUT_ANALOG);
> +			break;
> +		}
> +		fallthrough; /* 128b/132b */
>  	case TRANS_DDI_MODE_SELECT_DP_MST:
>  		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
>  		pipe_config->lane_count =
> -- 
> 2.20.1

-- 
Ville Syrjälä
Intel